Oct 29, 2022

Rare Earth elements synthesis confirmed in neutron star mergers

A group of researchers has, for the first time, identified rare earth elements produced by neutron star mergers.

Details of this milestone were published in The Astrophysical Journal on October 26, 2022.

When two neutron stars spiral inwards and merge, the resulting explosion produces a large amount of heavy elements that make up our Universe. The first confirmed example of this process was an event in 2017 named GW 170817. Yet, even five years later, identifying the specific elements created in neutron star mergers has eluded scientists, except for strontium identified in the optical spectra.

A research group led by Nanae Domoto, a graduate student at the Graduate School of Science at Tohoku University and a research fellow at the Japan Society for the Promotion of Science (JSPS), has systematically studied the properties of all heavy elements to decode the spectra from neutron star mergers.

They used this to investigate the spectra of kilonova -- bright emissions caused by the radioactive decay of freshly synthesized nuclei that are ejected during the merger -- from GW 170817. Based on comparisons of detailed kilonovae spectra simulations, produced by the supercomputer "ATERUI II" at the National Astronomical Observatory of Japan, the team found that the rare elements lanthanum and cerium can reproduce the near-infrared spectral features seen in 2017.

Until now, the existence of rare earth elements has only been hypothesized based on the overall evolution of the kilonova's brightness, but not from the spectral features.

"This is the first direct identification of rare elements in the spectra of neutron star mergers, and it advances our understanding of the origin of elements in the Universe," Dotomo said.

Read more at Science Daily

The brain cells that slow us down when we're sick

We tend to eat, drink, and move less when we're feeling under the weather. And we're not alone -- most animals reduce those same three behaviors when they're fighting an infection.

Now, a new study pinpoints the cluster of neurons that control these responses, referred to as sickness behaviors. By provoking immune responses in mice, researchers demonstrated that a specific population of cells in the brainstem potently induce three telltale sickness behaviors. In addition, inhibiting these neurons blunts each of these behavioral elements of the sickness response. The findings, published in Nature, directly link inflammation to neural pathways regulating behavior, offering insight into how the immune system interacts with the brain.

"We are still in the early days of trying to understand the brain's role in infection," says Jeffrey M. Friedman, Marilyn M. Simpson Professor at The Rockefeller University. "But with these results, we now have a unique opportunity to ask: What does your brain look like when you're sick?"

Sickness behaviors have been shown to play an important role in an animal's recovery from an infection. Prior studies have bolstered that theory by demonstrating that animals forced to eat when they're sick showed a significantly increased mortality. "These behavioral changes during infection are really important for survival," says lead author Anoj Ilanges, a former graduate student in Friedman's lab, now a group leader at the HHMI Janelia Research Campus

But it has never been clear how the brain coordinates that near-universal urge to refuse meals and curl up under the covers with the onset of infection. So Friedman and Ilanges set out to map the brain regions behind sickness behaviors in mice.

The team began by exposing mice to LPS, a piece of bacterial cell wall that activates the immune system and potently induces sickness behavior. Shortly after an injection of LPS, there was a spike in activity in a brainstem region known as the dorsal vagal complex, among a population of neurons expressing the neuropeptide ADCYAP1. To confirm that they had found the right brain cells, the researchers then activated those neurons in healthy mice and they found that the animals ate, drank, and moved around less. In contrast, when the ADCYAP1 neurons were deactivated , the effect of LPS on these behaviors was significantly reduced.

"We didn't know if the same or different neurons regulated each of these behaviors," Friedman says, "We found it surprising that a single neuronal population appears to regulate each of these components of the sickness response."

The authors were not, however, altogether surprised that this brainstem region was involved in mediating sickness behaviors. The dorsal vagal complex is one of a precious few physiological crossroads of the central nervous system, where an absence of the blood brain barrier enables circulating factors in the blood to pass information directly to the brain. "This region has emerged as a kind of alert center for the brain, conveying information about aversive or noxious substances that, more often than not, reduce food intake," Friedman says.

In the coming months, Friedman's team at Rockefeller intends to incorporate these findings into their overall goal of understanding the physiological signals and neural circuitry that regulate feeding behavior. They are specifically interested in understanding why even mice engineered to eat voraciously will nonetheless stop eating when exposed to bacterial infections.

Read more at Science Daily

River longer than the Thames beneath Antarctic ice sheet could affect ice loss

An unexpected river under the Antarctic ice sheet affects the flow and melting of ice, potentially accelerating ice loss as the climate warms.

The 460km-long river is revealed in a new study, which details how it collects water at the base of the Antarctic ice sheet from an area the size of Germany and France combined. Its discovery shows the base of the ice sheet has more active water flow than previously thought, which could make it more susceptible to changes in climate.

The discovery was made by researchers at Imperial College London, the University of Waterloo, Canada, Universiti Malaysia Terengganu, and Newcastle University, with the details published today in Nature Geoscience.

Co-author Professor Martin Siegert, from the Grantham Institute at Imperial College London, said: "When we first discovered lakes beneath the Antarctic ice a couple of decades ago, we thought they were isolated from each other. Now we are starting to understand there are whole systems down there, interconnected by vast river networks, just as they might be if there weren't thousands of metres of ice on top of them.

"The region where this study is based holds enough ice to raise the sea level globally by 4.3m. How much of this ice melts, and how quickly, is linked to how slippery the base of the ice is. The newly discovered river system could strongly influence this process."

Water can appear beneath ice sheets in two main ways: from surface meltwater running down through deep crevasses, or by melting at the base, caused by the natural heat of the Earth and friction as the ice moves over land.

However, the ice sheets around the north and south poles have different characteristics. In Greenland, the surface experiences strong melting over the summer months, where immense amounts of water channel down through deep crevasses called moulins.

In Antarctica, however, the surface doesn't melt in sufficient quantities to create moulins, as the summers are still too cold. It was thought this meant that there was relatively little water at the base of the Antarctic ice sheets.

The new discovery turns this idea on its head, showing there is sufficient water from basal melt alone to create huge river systems under kilometres-thick ice.

The discovery was made through a combination of airborne radar surveys that allow researchers to look beneath the ice and modelling of the ice sheet hydrology. The team focussed on a largely inaccessible and understudied area that includes ice from both the East and West Antarctic Ice Sheets and reaches the Weddell Sea.

That such a large system could be undiscovered until now is testament to how much we still need to learn about the continent, says lead researcher Dr Christine Dow from the University of Waterloo.

She said: "From satellite measurements we know which regions of Antarctica are losing ice, and how much, but we don't necessarily know why. This discovery could be a missing link in our models. We could be hugely underestimating how quickly the system will melt by not accounting for the influence of these river systems.

"Only by knowing why ice is being lost can we make models and predictions of how the ice will react in the future under further global heating, and how much this could raise global sea levels."

For example, the newly discovered river emerges into the sea beneath a floating ice shelf - where a glacier extending out from the land is buoyant enough to begin floating on the ocean water. The freshwater from the river however churns up warmer water towards the bottom of the ice shelf, melting it from below.

Co-author Dr Neil Ross, from the University of Newcastle, said: "Previous studies have looked at the interaction between the edges of ice sheets and ocean water to determine what melting looks like. However, the discovery of a river that reaches hundreds of kilometres inland driving some of these processes shows that we cannot understand the ice melt fully without considering the whole system: ice sheet, ocean, and freshwater."

The existence of large under-ice rivers also needs to be taken into account when predicting the possible consequences of climate change in the region. For example, if summers warm enough to cause enough surface melt that the water reaches the base of the ice sheet, it could have large effects on the river systems, potentially tipping Antarctica to a Greenland-like state, where ice loss is much faster.

There are also potential feedback loops that would accelerate ice loss. For example, if the ice starts to flow faster as water accumulated at the base, then this will increase friction where the ice runs over dry land, which could increase the amount of basal melting and water produced.

Read more at Science Daily

Oct 28, 2022

Traces of ancient ocean discovered on Mars

A recently released set of topography maps provides new evidence for an ancient northern ocean on Mars. The maps offer the strongest case yet that the planet once experienced sea-level rise consistent with an extended warm and wet climate, not the harsh, frozen landscape that exists today.

"What immediately comes to mind as one the most significant points here is that the existence of an ocean of this size means a higher potential for life," said Benjamin Cardenas, assistant professor of geosciences at Penn State and lead author on the study recently published in the Journal of Geophysical Research: Planets. "It also tells us about the ancient climate and its evolution. Based on these findings, we know there had to have been a period when it was warm enough and the atmosphere was thick enough to support this much liquid water at one time."

There has long been debate in the scientific community about whether Mars had an ocean in its low-elevation northern hemisphere, Cardenas explained. Using topography data, the research team was able to show definitive evidence of a roughly 3.5-billion-year-old shoreline with substantial sedimentary accumulation, at least 900 meters thick, that covered hundreds of thousands of square kilometers.

"The big, novel thing that we did in this paper was think about Mars in terms of its stratigraphy and its sedimentary record," Cardenas said. "On Earth, we chart the history of waterways by looking at sediment that is deposited over time. We call that stratigraphy, the idea that water transports sediment and you can measure the changes on Earth by understanding the way that sediment piles up. That's what we've done here -- but it's Mars."

The team used software developed by the United States Geological Survey to map data from the National Aeronautics and Space Administration (NASA) and the Mars Orbiter Laser Altimeter. They discovered over 6,500 kilometers of fluvial ridges and grouped them into 20 systems to show that the ridges are likely eroded river deltas or submarine-channel belts, the remnants of an ancient Martian shoreline.

Elements of rock formations, such as ridge-system thicknesses, elevations, locations and possible sedimentary flow directions helped the team understand the evolution of the region's paleogeography. The area that was once ocean is now known as Aeolis Dorsa and contains the densest collection of fluvial ridges on the planet, Cardenas explained.

"The rocks in Aeolis Dorsa capture some fascinating information about what the ocean was like," he said. "It was dynamic. The sea level rose significantly. Rocks were being deposited along its basins at a fast rate. There was a lot of change happening here."

Cardenas explained that on Earth, the ancient sedimentary basins contain the stratigraphic records of evolving climate and life. If scientists want to find a record of life on Mars, an ocean as big as the one that once covered Aeolis Dorsa would be the most logical place to start.

"A major goal for the Mars Curiosity rover missions is to look for signs of life," Cardenas said. "It's always been looking for water, for traces of habitable life. This is the biggest one yet. It's a giant body of water, fed by sediments coming from the highlands, presumably carrying nutrients. If there were tides on ancient Mars, they would have been here, gently bringing in and out water. This is exactly the type of place where ancient Martian life could have evolved."

Cardenas and his colleagues have mapped what they have determined are other ancient waterways on Mars. An upcoming study in the Journal of Sedimentary Research shows various outcrops visited by Curiosity rover were likely sedimentary strata from ancient river bars. Another paper published in Nature Geoscience applies an acoustic imaging technique used to view stratigraphy beneath the Gulf of Mexico's seafloor to a model of Mars-like basin erosion. The researchers determined the landforms called fluvial ridges, found widely across Mars, are likely ancient river deposits eroded from large basins similar to Aeolis Dorsa.

"The stratigraphy that we're interpreting here is quite similar to stratigraphy on Earth," Cardenas said. "Yes, it sounds like a big claim to say we've discovered records of large waterways on Mars, but in reality, this is relatively mundane stratigraphy. It's textbook geology once you recognize it for what it is. The interesting part, of course, is it's on Mars."

Read more at Science Daily

Passenger car preheating produces as much particulate emissions as driving dozens of kilometers

A new study from Finland, conducted by the University of Eastern Finland and Tampere University, measured particulate emissions from passenger car preheating with an auxiliary heater in sub-zero conditions. The preheating emissions were compared to calculated emissions from driving to determine the driving distance corresponding to the preheating emissions under current emissions standards.

Publishing their findings in Atmospheric Environment: X, the researchers measured auxiliary heater (AH) particulate emissions from the preheating of three gasoline, and three diesel cars for a half an hour period. Preheating was carried out outdoors in sub-zero conditions, i.e., when preheating is recommended by the AH manufacturer.

In terms of particulate emissions, using an auxiliary heater for half an hour was equivalent to a 97-kilometre drive in a gasoline car, or to a 20-kilometre drive in a diesel car, under current emissions standards.

"When driving short distances, vehicle preheating can produce significantly higher particulate emissions than the actual drive, especially when considering that the during-drive emissions of most cars are much lower than the limits set in the emissions standards," says Doctoral Researcher Henri Oikarinen of the University of Eastern Finland.

Auxiliary heaters produce a significant proportion of the preheating emissions on heater start-up and shut-down. This is particularly true for diesel operated heaters, for which steady heating (i.e., not turning the heater on and off) produces less than one third of the preheating emissions. In addition, a significant proportion of the particles produced by auxiliary heaters were observed to be in the smallest nanometric range: more than 50% of the particles produced by gasoline operated heaters, and more than 90% of the particles produced by diesel operated heaters, were in the below 23 nm range.

"However, preheating extends the life cycle of the vehicle and also makes driving more comfortable. These findings do not suggest that people should stop preheating their cars; instead, we could reduce the emissions from preheating by using similar emissions reduction methods that are in place for engine emissions, also for fuel-operated auxiliary heaters. Fuel-operated heaters could also be switched for electric ones," Senior Researcher Panu Karjalainen of Tampere University says.

Current vehicle emissions standards apply to particles above 23 nanometres in size, i.e., the observed large quantity of particles below 23 nanometres in size is significant and raises the question of whether the emissions of these smaller particles, too, should be regulated.

In new cars, an auxiliary heater may be needed also during drive

Fuel-operated auxiliary heaters are used for heating vehicles in cold conditions. Auxiliary heaters are commonly known as 'Webasto' or 'Eberspächer', which are the largest AH manufacturers. Particulate emissions from auxiliary heaters are not regulated by legislation, and research into these emissions is scarce. As a result, the impact of AH emissions on air quality and, consequently, on health and the global emissions budget, remains unknown. However, studying AH emissions is essential to gain an accurate understanding of the total emissions from vehicles.

In recent years, vehicle engine emissions have been significantly reduced by emission after-treatment methods such as particulate filters and carburetors, and by improving engine efficiency. Existing auxiliary heaters, however, do not have similar after-treatment methods that are in place for vehicle engine emissions.

The significance of AH emissions is emphasised especially for certain new vehicle models whose engine performance is so efficient that they do not produce enough heat during the drive in sub-zero conditions. In these cases, an auxiliary heater is needed for heating the vehicle also during the drive.

Read more at Science Daily

Companies' 'deforestation-free' supply chain pledges have barely impacted forest clearance in the Amazon, researchers say

More companies must make and implement zero-deforestation supply chain commitments in order to significantly reduce deforestation and protect diverse ecosystems, say researchers.

Corporate pledges not to buy soybeans produced on land deforested after 2006 have reduced tree clearance in the Brazilian Amazon by just 1.6% between 2006 and 2015.

This equates to a protected area of 2,300 km2 in the Amazon rainforest: barely the size of Oxfordshire in the UK.

The findings, made by tracing traders' soy supplies back to their source, are published today in the journal Environmental Research Letters. The work involved a team from the University of Cambridge, Boston University, ETH Zurich and New York University.

The researchers also discovered that in the Cerrado, Brazil's tropical savannah, zero-deforestation commitments have not been adopted effectively -- leaving over 50% of soy-suitable forests and their biodiversity without protection.

Brazil has the largest remaining tropical forests on the planet, but these are being rapidly cleared to rear cattle and grow crops including soybean. Demand for soy is surging around the world, and an estimated 4,800 km2 of rainforest is cleared each year to grow soybeans.

The majority of soy is consumed indirectly by humans: soybean is widely used as feed for factory-farmed chickens, pigs, fish and cattle. It also accounts for around 27% of global vegetable oil production, and as a complete protein source it often forms a key part of vegetarian and vegan diets.

By 2021, at least 94 companies had adopted zero-deforestation commitments -- pledging to eliminate deforestation from their supply chains. But the study revealed that many of these commitments are not put into practice.

And the researchers say that adoption of zero-deforestation commitments is lagging among small and medium sized food companies.

"Zero-deforestation pledges are a great first step, but they need to be implemented to have an effect on forests -- and right now it's mainly the bigger companies that have the resources to do this," said Professor Rachael Garrett, Moran Professor of Conservation and Development at the University of Cambridge Conservation Research Institute, a joint senior author of the report.

She added: "If soybean traders actually implemented their global commitments for zero-deforestation production, current levels of forest clearance in Brazil could be reduced by around 40 percent."

Deforestation is the second largest contributor to global greenhouse gas emissions after fossil fuel use. It also causes the loss of diverse animal and plant life, threatens the livelihoods of indigenous groups, and increases inequality and conflict.

The researchers say that the supply chains of other food products including cattle, oil palm and cocoa supply chains are more complex than soy, making them even more difficult to monitor.

"If supply chain policies intend to contribute to the task of tackling deforestation in Brazil, it's crucial to expand zero-deforestation supply chain policies beyond soy," said Garrett, who is also Professor of Environmental Policy at ETH Zurich.

A 'soy moratorium' was the first voluntary zero-deforestation commitment in the tropics -- by signing it, companies agreed not to buy soybeans produced on land deforested after 2006. But while the commitment was implemented in the Brazilian Amazon, most Brazilian soy is produced in the Cerrado -- which is rich in biodiversity.

The researchers say their findings suggest private sector efforts are not enough to halt deforestation: supportive political leadership is also vital to conservation efforts.

"Supply chain governance should not be a substitute for state-led forest policies, which are critical to enable zero deforestation monitoring and enforcement, have better potential to cover different crops, land users, and regions," said Garrett.

Read more at Science Daily

We need to stop thinking of insects as 'creepy crawlies' and recognize their keystone role in ecosystems

We need to stop thinking of insects as creepy crawlies and focus on the huge benefits they bring to people and the natural environment, scientists say.

The widespread and deeply ingrained cultural perception of insects as creepy crawlies is a key factor holding back the public's appreciation of the role they play within ecosystems. This perception is in part reflected in government biodiversity policy inaction across the globe, they argue.

This point is among a range of actions highlighted as part of a new paper published in Ecology and Evolution produced by an international team of entomologists which outlines a 'battle plan' including steps needed to prevent further insect losses across the globe.

Led by Dr Philip Donkersley of Lancaster University and co-authored by scientists from the University of Hong Kong, the Czech Academy of Sciences and Harper Adams University, the paper is a call to action targeted at other entomologists to step up advocacy for insects.

Despite 30 years of intergovernmental reports highlighting biodiversity targets, global insect abundance, biomass and diversity continues to decline. The paper considers the lack of progress in protecting insects and why meaningful change has not happened.

"Biodiversity, including insect, declines are often unintended consequences of human activities with human wellbeing nearly always trumping nature conservation, and this is likely to continue until we reach a point where we see flat-lining ecosystems are detrimental to our own species," said Dr Donkersley. "Intergovernmental action has been slow to respond, kicking in only when change becomes impossible to ignore. If we are to see political attitudes and actions change then first societies' perception of insects needs to be addressed."

The paper highlights the range of benefits that insects bring, including some that are lesser known. These benefits include fundamental roles within ecosystems through interactions with plants including as pollinators, as a food for other animals, and as a food source for people in many parts of the world. Other benefits the authors highlight include insects' contributions to wellbeing, culture and innovation, such as the benefits people derive from seeing butterflies in parks and gardens, their inclusion in poetry and literature, and their inspiration for a range of technologies, cosmetics and pharmaceuticals.

The researchers have outlined strategic priorities in their action plan to help support the conservation of insects. These include:
 

  • to proactively and publicly address government inaction
  • highlighting the technological developments we owe to the insects, and that there is a lot still to be discovered
  • aligning with bird, plant and mammal conservation groups to show species interdependencies and knock-on benefits insect conservation has for other animals
  • Engage public and school students with the wonders of the insect world to counter perceptions of insects as threatening 'creepy crawlies'


"The benefits we gain from the insect world are broad, yet aversion of phobias of invertebrates are common and stand firmly in the path of their conservation," said Dr Donkersley. "We need to move beyond this mindset and appreciate the huge role they play in ecosystems, foodchains, mental health, and even technological innovation.

"This perception change is a crucial step, alongside other measures we outline in this paper. Immediate and substantial actions are needed to protect insect species in order to maintain global ecosystem stability."

Read more at Science Daily

Oct 27, 2022

Magma on Mars likely

Since 2018, when the NASA InSight Mission deployed the SEIS seismometer on the surface of Mars, seismologists and geophysicists at ETH Zurich have been listening to the seismic pings of more than 1,300 marsquakes. Again and again, the researchers registered smaller and larger Mars quakes. A detailed analysis of the quakes' location and spectral character brought a surprise. With epicentres originating in the vicinity of the Cerberus Fossae -- a region consisting of a series of rifts or graben -- these quakes tell a new story. A story that suggests vulcanism still plays an active role in shaping the Martian surface.

Mars shows signs of life and youth

An international team of researchers, led by ETH Zurich, analysed a cluster of more than 20 recent marsquakes that originated in the Cerberus Fossae graben system. From the seismic data, scientists concluded that the low-frequency quakes indicate a potentially warm source that could be explained by present day molten lava, i.e., magma at that depth, and volcanic activity on Mars. Specifically, they found that the quakes are located mostly in the innermost part of Cerberus Fossae.

When they compared seismic data with observational images of the same area, they also discovered darker deposits of dust not only in the dominant direction of the wind, but in multiple directions surrounding the Cerebus Fossae Mantling Unit. "The darker shade of the dust signifies geological evidence of more recent volcanic activity -- perhaps within the past 50,000 years -- relatively young, in geological terms," explains Simon Staehler, the lead author of the paper, which has now been published in the journal Nature. Staehler is a Senior Scientist working in the Seismology and Geodynamics group led by Professor Domenico Giardini at the Institute of Geophysics, ETH Zurich.

Why study the terrestrial neighbour?

Exploring Earth's planetary neighbours is no easy task. Mars is the only planet, other than Earth, in which scientists have ground-based rovers, landers, and now even drones that transmit data. All other planetary exploration, so far, has relied on orbital imagery. "InSight's SEIS is the most sensitive seismometer ever installed on another planet," says Domenico Giardini. "It affords geophysicists and seismologists an opportunity to work with current data showing what is happening on Mars today -- both at the surface and in its interior." The seismic data, along with orbital images, ensures a greater degree of confidence for scientific inferences.

One of our nearest terrestrial neighbours, Mars is important for understanding similar geological processes on Earth. The red planet is the only one we know of, so far, that has a core composition of iron, nickel, and sulphur that might have once supported a magnetic field. Topographical evidence also indicates that Mars once held vast expanses of water and possibly a denser atmosphere. Even today, scientists have learned that frozen water, although possibly mostly dry ice, still exists on its polar caps. "While there is much more to learn, the evidence of potential magma on Mars is intriguing," Anna Mittelholz, Postdoctoral Fellow at ETH Zurich and Harvard University.

Last remnants of geophysical life

Looking at images of the vast dry, dusty Martian landscape it is difficult to imagine that about 3.6 billion years ago Mars was very much alive, at least in a geophysical sense. It spewed volcanic debris for a long enough time to give rise to Tharsis Montes region, the largest volcanic system in our solar system and the Olympus Mons -- a volcano nearly three times the elevation of Mount Everest. The quakes coming from the nearby Cerberus Fossae -- named for a creature from Greek mythology known as the "hell-hound of Hades" that guards the underworld -- suggest that Mars is not quite dead yet. Here the weight of the volcanic region is sinking and forming parallel graben (or rifts) that pull the crust of Mars apart, much like the cracks that appear on the top of a cake while its baking. According to, Staehler "it is possible that what we are seeing are the last remnants of this once active volcanic region or that the magma is right now moving eastward to the next location of eruption."

Read more at Science Daily

Ozone hole continues shrinking in 2022, NASA and NOAA scientists say

The annual Antarctic ozone hole reached an average area of 8.9 million square miles (23.2 million square kilometers) between Sept. 7 and Oct. 13, 2022. This depleted area of the ozone layer over the South Pole was slightly smaller than last year and generally continued the overall shrinking trend of recent years.

"Over time, steady progress is being made, and the hole is getting smaller," said Paul Newman, chief scientist for Earth sciences at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "We see some wavering as weather changes and other factors make the numbers wiggle slightly from day to day and week to week. But overall, we see it decreasing through the past two decades. The elimination of ozone-depleting substances through the Montreal Protocol is shrinking the hole."

The ozone layer -- the portion of the stratosphere that protects our planet from the Sun's ultraviolet rays -- thins to form an "ozone hole" above the South Pole every September. Chemically active forms of chlorine and bromine in the atmosphere, derived from human-produced compounds, attach to high-altitude polar clouds each southern winter. The reactive chlorine and bromine then initiate ozone-destroying reactions as the Sun rises at the end of Antarctica's winter.

Researchers at NASA and NOAA detect and measure the growth and breakup of the ozone hole with instruments aboard the Aura, Suomi NPP, and NOAA-20 satellites. On Oct. 5, 2022, those satellites observed a single-day maximum ozone hole of 10.2 million square miles (26.4 million square kilometers), slightly larger than last year.

When the polar sun rises, NOAA scientists also make measurements with a Dobson Spectrophotometer, an optical instrument that records the total amount of ozone between the surface and the edge of space -- known as the total column ozone value. Globally, the total column average is about 300 Dobson Units. On Oct. 3, 2022, scientists recorded a lowest total-column ozone value of 101 Dobson Units over the South Pole. At that time, ozone was almost completely absent at altitudes between 8 and 13 miles (14 and 21 kilometers) -- a pattern very similar to last year.

Some scientists were concerned about potential stratospheric impacts from the January 2022 eruption of the Hunga Tonga-Hunga Ha'apai volcano. The 1991 Mount Pinatubo eruption released substantial amounts of sulfur dioxide that amplified ozone layer depletion. However, no direct impacts from Hunga Tonga have been detected in the Antarctic stratospheric data.

Read more at Science Daily

Trunk dexterity explained: Scientists decipher facial motor control in elephants

Elephants have an amazing arsenal of face, ear and trunk movements. The trunk consists of far more muscles than the entire human body and can perform both powerful and very delicate movements. A team of scientists from the Humboldt University of Berlin and the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) now examined the facial motor nucleus of African and Asian elephants, the brain structure that controls the facial muscles of these animals. This nucleus contains more facial motor neurons than in any other terrestrial mammal, the scientists show in a paper published in the journal Science Advances. African elephants in particular have particularly prominent neuron clusters for the control of the trunk "fingers."

One of the most remarkable body parts in the animal kingdom is the elephant trunk. It is extremely muscular and strong, containing far more muscles than the entire human body, and yet it is very sensitive and capable of carefully performed, finely tuned motor actions. The way elephants use the tip of their trunk strongly resembles a human hand, and they actually have so-called fingers at the tip. Lena Kaufmann and colleagues in Michael Brecht's laboratory at HU Berlin and Thomas Hildebrandt's Department of Reproduction Management at the Leibniz-IZW for the first time have now studied and described in detail the so-called elephant facial nucleus -- the brain structure responsible for controlling the elephants' facial muscles, from the ears to the tip of the trunk.

"The elephant's facial motor nucleus is unique in several ways. For example, it contains more facial motor neurons than all other terrestrial mammals," says first author Lena Kaufmann (HU Berlin). The scientists counted about 54,000 neurons in the facial nucleus of Asian elephants (Elephas maximus), whereas the African savanna elephant (Loxodonta africana) even has about 63,000. The team attributed the higher number of facial nucleus neurons in African savanna elephants to their larger ears and more elaborate trunk tip. "African savanna elephants have two so-called fingers at the trunk tip with which they grip objects," says Thomas Hildebrandt (Leibniz-IZW). "This kind of pincer grip requires much dexterity with the trunk tip. Not surprisingly, we see in the brains of African elephants prominent neuron clusters for the control of the fingertips." Asian elephants have only one finger and tend to wrap their trunk around objects; hence their finger-tip is less prominently represented in their brain.

Read more at Science Daily

Why some people are mosquito magnets

It's impossible to hide from a female mosquito -- she will hunt down any member of the human species by tracking our CO2 exhalations, body heat, and body odor. But some of us are distinct "mosquito magnets" who get more than our fair share of bites. Blood type, blood sugar level, consuming garlic or bananas, being a woman, and being a child are all popular theories for why someone might be a preferred snack. Yet for most of them, there is little credible data, says Leslie Vosshall, head of Rockefeller's Laboratory of Neurogenetics and Behavior.

This is why Vosshall and Maria Elena De Obaldia, a former postdoc in her lab, set out to explore the leading theory to explain varying mosquito appeal: individual odor variations connected to skin microbiota. They recently demonstrated through a study that fatty acids emanating from the skin may create a heady perfume that mosquitoes can't resist. They published their results in Cell.

"There's a very, very strong association between having large quantities of these fatty acids on your skin and being a mosquito magnet," says Vosshall, the Robin Chemers Neustein Professor at The Rockefeller University and Chief Scientific Officer of the Howard Hughes Medical Institute.

A tournament no one wants to win


In the three-year study, eight participants were asked to wear nylon stockings over their forearms for six hours a day. They repeated this process on multiple days. Over the next few years, the researchers tested the nylons against each other in all possible pairings through a round-robin style "tournament." They used a two-choice olfactometer assay that De Obaldia built, consisting of a plexiglass chamber divided into two tubes, each ending in a box that held a stocking. They placed Aedes Aegypti mosquitoes -- the primary vector species for Zika, dengue, yellow fever, and chikungunya -- in the main chamber and observed as the insects flew down the tubes towards one nylon or the other.

By far the most compelling target for Aedes aegypti was Subject 33, who was four times more attractive to the mosquitoes than the next most-attractive study participant, and an astonishing 100 times more appealing than the least attractive, Subject 19.

The samples in the trials were de-identified, so the experimenters didn't know which participant had worn which nylon. Still, they would notice that something unusual was afoot in any trial involving Subject 33, because insects would swarm towards that sample. "It would be obvious within a few seconds of starting the assay," says De Obaldia. "It's the type of thing that gets me really excited as a scientist. This is something real. This is not splitting hairs. This is a huge effect."

The researchers sorted the participants into high and low attractors, and then asked what differentiated them. They used chemical analysis techniques to identify 50 molecular compounds that were elevated in the sebum (a moisturizing barrier on the skin) of the high-attracting participants. From there, they discovered that mosquito magnets produced carboxylic acids at much higher levels than the less-attractive volunteers. These substances are in the sebum and are used by bacteria on our skin to produce our unique human body odor.

To confirm their findings, Vosshall's team enrolled another 56 people for a validation study. Once again, Subject 33 was the most alluring, and stayed so over time.

"Some subjects were in the study for several years, and we saw that if they were a mosquito magnet, they remained a mosquito magnet," says De Obaldia. "Many things could have changed about the subject or their behaviors over that time, but this was a very stable property of the person."

Even knockouts find us


Humans produce mainly two classes of odors that mosquitoes detect with two different sets of odor receptors: Orco and IR receptors. To see if they could engineer mosquitoes unable to spot humans, the researchers created mutants that were missing one or both of the receptors. Orco mutants remained attracted to humans and able to distinguish between mosquito magnets and low attractors, while IR mutants lost their attraction to humans to a varying degree, but still retained the ability to find us.

These were not the results the scientists were hoping for. "The goal was a mosquito that would lose all attraction to people, or a mosquito that had a weakened attraction to everybody and couldn't discriminate Subject 19 from Subject 33. That would be tremendous," Vosshall says, because it could lead to the development of more effective mosquito repellents. "And yet that was not what we saw. It was frustrating."

These results complement one of Vosshall's recent studies, also published in Cell, which revealed the redundancy of Aedes aegypti's exquisitely complex olfactory system. It's a failsafe that the female mosquito relies on to live and reproduce. Without blood, she can't do either. That's why "she has a backup plan and a backup plan and a backup plan and is tuned to these differences in the skin chemistry of the people she goes after," Vosshall says.

The apparent unbreakability of the mosquito scent tracker makes it difficult to envision a future where we're not the number-one meal on the menu. But one potential avenue is to manipulate our skin microbiomes. It is possible that slathering the skin of a high-appeal person like Subject 33 with sebum and skin bacteria from the skin of a low-appeal person like Subject 19 could provide a mosquito-masking effect.

"We haven't done that experiment," Vosshall notes. "That's a hard experiment. But if that were to work, then you could imagine that by having a dietary or microbiome intervention where you put bacteria on the skin that are able to somehow change how they interact with the sebum, then you could convert someone like Subject 33 into a Subject 19. But that's all very speculative."

Read more at Science Daily

Oct 26, 2022

Astronomy: Observation puzzles researchers

An international team of astrophysicists has made a puzzling discovery while analyzing certain star clusters. The University of Bonn played a major role in the study. The finding challenges Newton's laws of gravity, the researchers write in their publication. Instead, the observations are consistent with the predictions of an alternative theory of gravity. However, this is controversial among experts. The results have now been published in the Monthly Notices of the Royal Astronomical Society.

In their work, the researchers investigated the so-called open star clusters. These are formed when thousands of stars are born within a short time in a huge gas cloud. As they "ignite," the galactic newcomers blow away the remnants of the gas cloud. In the process, the cluster expands considerably. This creates a loose formation of several dozen to several thousand stars. The weak gravitational forces acting between them hold the cluster together.

"In most cases, open star clusters survive only a few hundred million years before they dissolve," explains Prof. Dr. Pavel Kroupa of the Helmholtz Institute of Radiation and Nuclear Physics at the University of Bonn. In the process, they regularly lose stars, which accumulate in two so-called "tidal tails." One of these tails is pulled behind the cluster as it travels through space. The other, in contrast, takes the lead like a spearhead.

"According to Newton's laws of gravity, it's a matter of chance in which of the tails a lost star ends up," explains Dr. Jan Pflamm-Altenburg of the Helmholtz Institute of Radiation and Nuclear Physics. "So both tails should contain about the same number of stars. However, in our work we were able to prove for the first time that this is not true: In the clusters we studied, the front tail always contains significantly more stars nearby to the cluster than the rear tail."

New method developed for counting stars

Until now, it has been almost impossible to determine from among the millions of stars close to a cluster those that belong to its tails. "To do this, you have to look at the velocity, direction of motion and age of each of these objects," explains Dr. Tereza Jerabkova. The co-author of the paper, who did her doctorate in Kroupa's group, recently moved from the European Space Agency (ESA) to the European Southern Observatory in Garching. She developed a method that allowed her to accurately count the stars in the tails for the first time. "So far, five open clusters have been investigated near us, including four by us," she says. "When we analyzed all the data, we encountered the contradiction with the current theory. The very precise survey data from ESA's Gaia space mission were indispensable for this."

The observational data, in contrast, fit much better with a theory that goes by the acronym MOND ("MOdified Newtonian Dynamics") among experts. "Put simply, according to MOND, stars can leave a cluster through two different doors," Kroupa explains. "One leads to the rear tidal tail, the other to the front. However, the first is much narrower than the second -- so it's less likely that a star will leave the cluster through it. Newton's theory of gravity, on the other hand, predicts that both doors should be the same width."

Star clusters are shorter-lived than Newton's laws predict

The team calculated the stellar distribution expected according to MOND. "The results correspond surprisingly well with the observations," highlights Dr. Ingo Thies, who played a key role in the corresponding simulations. "However, we had to resort to relatively simple computational methods to do this. We currently lack the mathematical tools for more detailed analyses of modified Newtonian dynamics." Nevertheless, the simulations also coincided with the observations in another respect: They predicted how long open star clusters should typically survive. And this time span is significantly shorter than would be expected according to Newton's laws. "This explains a mystery that has been known for a long time," Kroupa points out. "Namely, star clusters in nearby galaxies seem to be disappearing faster than they should."

Read more at Science Daily

Laying geological groundwork for life on Earth

New research analyzing pieces of the most ancient rocks on the planet adds some of the sharpest evidence yet that Earth's crust was pushing and pulling in a manner similar to modern plate tectonics at least 3.25 billion years ago. The study also provides the earliest proof of when the planet's magnetic north and south poles swapped places.

The two results offer clues into how such geological changes may have resulted in an environment more conducive to the development of life on the planet.

The work, described in PNAS and led by Harvard geologists Alec Brenner and Roger Fu, focused on a portion of the Pilbara Craton in western Australia, one of the oldest and most stable pieces of the Earth's crust. Using novel techniques and equipment, the researchers show that some of the Earth's earliest surface was moving at a rate of 6.1 centimeters per year and 0.55 degrees every million years.

That speed more than doubles the rate the ancient crust was shown to be moving in a previous study by the same researchers. Both the speed and direction of this latitudinal drift leaves plate tectonics as the most logical and strongest explanations for it.

"There's a lot of work that seems to suggest that early in Earth's history plate tectonics wasn't actually the dominant way in which the planet's internal heat gets released as it is today through the shifting of plates," said Brenner, a Ph.D. candidate in the Graduate School of Arts and Sciences and member of Harvard's Paleomagnetics Lab. "This evidence lets us much more confidently rule out explanations that don't involve plate tectonics."

For example, the researchers can now argue against phenomena called "true polar wander" and "stagnant lid tectonics," which can both cause the Earth's surface to shift but aren't part of modern-style plate tectonics. The results lean more toward plate tectonic motion because the newly discovered higher rate of speed is inconsistent with aspects of the other two processes.

In the paper, the scientists also describe what's believed to be the oldest evidence of when Earth reversed its geomagnetic fields, meaning the magnetic North and South Pole flipped locations. This type of flip-flop is a common occurrence in Earth's geologic history with the pole's reversing 183 times in the last 83 million years and perhaps several hundred times in the past 160 million years, according to NASA.

The reversal tells a great deal about the planet's magnetic field 3.2 billion years ago. Key among these implications is that the magnetic field was likely stable and strong enough to keep solar winds from eroding the atmosphere. This insight, combined with the results on plate tectonics, offers clues to the conditions under which the earliest forms of life developed.

"It paints this picture of an early earth that was already really geodynamically mature," Brenner said. "It had a lot of the same sorts of dynamic processes that result in an Earth that has essentially more stable environmental and surface conditions, making it more feasible for life to evolve and develop."

Today, the Earth's outer shell consists of about 15 shifting blocks of crust, or plates, which hold the planet's continents and oceans. Over eons the plates drifted into each other and apart, forming new continents and mountains and exposing new rocks to the atmosphere, which led to chemical reactions that stabilized Earth's surface temperature over billions of years.

Evidence of when plate tectonics started is hard to come by because the oldest pieces of crust are thrust into the interior mantle, never to resurface. Only 5 percent of all rocks on Earth are older than 2.5 billion years old, and no rock is older than about 4 billion years.

Overall, the study adds to growing research that tectonic movement occurred relatively early in Earth's 4.5-billion-year history and that early forms of life came about in a more moderate environment. Members of the project revisited the Pilbara Craton in 2018, which stretches about 300 miles across. They drilled into the primordial and thick slab of crust there to collect samples that, back in Cambridge, were analyzed for their magnetic history.

Using magnetometers, demagnetizing equipment, and the Quantum Diamond Microscope -- which images the magnetic fields of a sample and precisely identifies the nature of the magnetized particles -- the researchers created a suite of new techniques for determining the age and way the samples became magnetized. This allows the researchers to determine how, when, and which direction the crust shifted as well as the magnetic influence coming from Earth's geomagnetic poles.

The Quantum Diamond Microscope was developed in a collaboration between Harvard researchers in the Departments of Earth and Planetary Sciences (EPS) and of Physics.

For future studies, Fu and Brenner plan keep their focus on the Pilbara Craton while also looking beyond it to other ancient crusts around the world. They hope to find older evidence of modern-like plate motion and when the Earth's magnetic poles flipped.

Read more at Science Daily

Earth is 'unequivocally' in midst of climate emergency, scientists say

An international coalition of researchers says in a report published today that the Earth's vital signs have worsened to the point that "humanity is unequivocally facing a climate emergency."

The report, "World Scientists' Warning of a Climate Emergency 2022," published in the journal BioScience, notes that 16 of 35 planetary vital signs the authors use to track climate change are at record extremes.

The report's authors share new data illustrating increasing frequency of extreme heat events, rising global tree cover loss because of fires, and a greater prevalence of the mosquito-borne dengue virus.

They also note large increases in fossil fuel energy consumption following COVID-19 pandemic shutdowns -- despite an upswing in commitments for fossil fuel divestment -- and a rise in atmospheric carbon dioxide levels to 418 parts per million, the highest on record.

William Ripple, a distinguished professor in the OSU College of Forestry, and postdoctoral researcher Christopher Wolf are the lead authors of the report, and 10 other U.S. and global scientists are co-authors. The report follows by five years the "World Scientists' Warning to Humanity: A Second Notice" published by Ripple in in BioScience and co-signed by more than 15,000 scientists in 184 countries.

"As we can see by the annual surges in climate disasters, we are now in the midst of a major climate crisis, with far worse to come if we keep doing things the way we've been doing them," Wolf said. "We implore our fellow scientists to join us in advocating for research-based approaches to climate and environmental decision-making."

Other co-authors of the report are from UCLA, the University of Sydney, Independent University Bangladesh, the University of Cambridge, the University of Exeter, Bezos Earth Fund and the Potsdam Institute for Climate Impact Research.

"Climate change is not a standalone issue," said Saleemul Huq of Independent University Bangladesh. "It is part of a larger systemic problem of ecological overshoot where human demand is exceeding the regenerative capacity of the biosphere. To avoid more untold human suffering, we need to protect nature, eliminate most fossil fuel emissions and support socially just climate adaptations with a focus on low-income areas that are most vulnerable."

The report points out that in the three decades since more than 1,700 scientists signed the original "World Scientists' Warning to Humanity" in 1992, global greenhouse gas emissions have increased by 40%.

"As Earth's temperatures are creeping up, the frequency or magnitude of some types of climate disasters may actually be leaping up," said the University of Sydney's Thomas Newsome. "We urge our fellow scientists around the world to speak out on climate change."

In addition to Wolf and Ripple, three other OSU scientists are co-authors of the paper: Jillian Gregg, Matthew Betts and Beverly Law.

"World Scientists' Warning of a Climate Emergency 2022" is an update of a paper published in BioScience three years ago. The Alliance of World Scientists, an independent organization formed to be a collective voice on environmental sustainability and human well-being, continues to collect co-signers on the 2019 paper. To date more than 14,000 scientists from 158 countries have signed.

Ongoing work to spur climate change action by scientists around the world is chronicled in a new 35-minute documentary film "The Scientist's Warning." The film, by Oregon State Productions, is now available for free online viewing (see: https://scientistswarning.forestry.oregonstate.edu/) following its Oct. 14 premiere at the Newport Beach Film Festival in Newport Beach, California.

"The Scientist's Warning" also chronicles Ripple's personal journey: from a rural, low-income childhood in South Dakota in the 1950s to becoming an ecologist in Yellowstone to assuming a role as a global advocate for using science to make informed policy decisions.

"Look at all of these fires, floods and massive storms," Ripple said. "The specter of climate change is at the door and pounding hard."

Read more at Science Daily

Chemical clues to the mystery of what's coating Stradivari's violins

Stradivarius violins produce elegant music with a level of clarity that is unparalleled by modern instruments, according to some musicians. And it's the finishing touches -- mysterious treatments applied hundreds of years ago by Antonio Stradivari -- that contribute to their unique look and sound. In a step toward unraveling the secret, researchers in ACS' Analytical Chemistry report on a nanometer-scale imaging of two of Stradivari's violins, revealing a protein-based layer between the wood and varnish.

Previous studies have reported that some stringed instruments crafted by Stradivari have a hidden coating underneath the shiny varnish. This coating's purpose would have been to fill in and smooth out the wood, influencing the wood's resonance and the sound that's produced. Knowing the components of this film could be key to replicating the historic instruments in modern times. So, Lisa Vaccari, Marco Malagodi and colleagues wanted to find a technique that would determine the composition of the layer between the wood and varnish of two precious violins -- the San Lorenzo 1718 and the Toscano 1690.

Using a technique previously used on historic violins, synchrotron radiation Fourier-transform infrared spectromicroscopy, the team found that both samples had an intermediary layer, but this method couldn't differentiate the layer's composition from the adjacent wood. Then they turned to infrared scattering-type scanning near field microscopy (IR s-SNOM) to analyze the samples. The IR s-SNOM apparatus includes a microscope that collects images tens of nanometers wide and measures the infrared light scattered from the coating layer and the wood to collect information about their chemical composition. The results of the new method showed that the layer between the wood and varnish of both instruments contained protein-based compounds, congregating in nano-sized patches. Because IR s-SNOM provided a detailed 3D picture of the types of substances on the violin's surface, the researchers say that it could be used in future studies to identify compounds in complex multi-layer cultural heritage samples.

Read more at Science Daily

Oct 25, 2022

Ancient bacteria might lurk beneath Mars' surface

When Mars' first samples return to Earth, scientists should be on the lookout for ancient sleeping bacteria, a new study has found.

In a first-of-its-kind study, a research team, including Northwestern University's Brian Hoffman and Ajay Sharma, found that ancient bacteria could survive close to the surface on Mars much longer than previously assumed. And -- when the bacteria are buried and, thus, shielded from galactic cosmic radiation and solar protons -- they can survive much longer.

These findings strengthen the possibility that if life ever evolved on Mars, its biological remains might be revealed in future missions, including ExoMars (Rosalind Franklin rover) and the Mars Life Explorer, which will carry drills to extract materials from 2 meters below the surface.

And because the scientists proved that certain strains of bacteria can survive despite Mars' harsh environment, future astronauts and space tourists could inadvertently contaminate Mars with their own hitchhiking bacteria.

The paper will be published on Tuesday (Oct. 25) in the journal Astrobiology.

"Our model organisms serve as proxies for both forward contamination of Mars, as well as backward contamination of Earth, both of which should be avoided," said Michael Daly, a professor of pathology at Uniformed Services University of the Health Sciences (USU) and member of the National Academies' Committee on Planetary Protection, who led the study. "Importantly, these findings have biodefense implications, too, because the threat of biological agents, such as Anthrax, remains a concern to military and homeland defense."

"We concluded that terrestrial contamination on Mars would essentially be permanent -- over timeframes of thousands of years," said Hoffman, a senior co-author of the study. "This could complicate scientific efforts to look for Martian life. Likewise, if microbes evolved on Mars, they could be capable of surviving until present day. That means returning Mars samples could contaminate Earth."

Hoffman is the Charles E. and Emma H. Morrison Professor of Chemistry and professor of molecular biosciences in Northwestern's Weinberg College of Arts and Sciences. He also is a member of the Chemistry of Life Processes Institute.

Simulating Mars

The environment on Mars is harsh and unforgiving. The arid and freezing conditions, which average -80 degrees Fahrenheit (-63 degrees Celsius) at mid-latitudes, make the Red Planet seem inhospitable to life. Even worse: Mars also is constantly bombarded by intense galactic cosmic radiation and solar protons.

To explore whether or not life could survive in these conditions, Daly, Hoffman and their collaborators first determined the ionizing radiation survival limits of microbial life. Then, they exposed six types of Earthling bacteria and fungi to a simulated Martian surface -- which is frozen and dry -- and zapped them with gamma rays or protons (to mimic radiation in space).

"There is no flowing water or significant water in the Martian atmosphere, so cells and spores would dry out," Hoffman said. "It also is known that the surface temperature on Mars is roughly similar to dry ice, so it is indeed deeply frozen."

Ultimately, the researchers determined that some terrestrial microorganisms potentially could survive on Mars over geologic timescales of hundreds of millions of years. In fact, the researchers discovered that one robust microbe, Deinococcus radiodurans (affectionately known as "Conan the Bacterium"), is particularly well-suited to surviving Mars' harsh conditions. In the novel experiments, Conan the Bacterium survived astronomical amounts of radiation in the freezing, arid environment -- far outlasting Bacillus spores, which can survive on Earth for millions of years.

Radical radiation

To test the effects of radiation, the team exposed samples to large doses of gamma radiation and protons -- typical to what Mars receives in the near subsurface -- and far smaller doses, which would occur if a microorganism was deeply buried.

Then, Hoffman's team at Northwestern used an advanced spectroscopy technique to measure the accumulation of manganese antioxidants in the radiated microorganisms' cells. According to Hoffman, the size of the radiation dose that a microorganism or its spores can survive correlates with the amount of manganese antioxidants it contains. Therefore, more manganese antioxidants means more resistance to radiation -- and more enhanced survival.

In earlier studies, previous researchers found that Conan the Bacterium, when suspended in liquid, can survive 25,000 units of radiation (or "grays"), the equivalent to about 1.2 million years just below Mars' surface. But the new study found that when the hearty bacterium is dried, frozen and deeply buried -- which would be typical to a Martian environment -- it could weather 140,000 grays of radiation. This dose is 28,000 times greater than what would kill a human.

Although Conan the Bacterium could only survive for a few hours at the surface while bathed in ultraviolet light, its lifetime improves dramatically when its shaded or located directly below Mars' surface. Buried just 10 centimeters below the Martian surface, Conan the Bacterium's survival period increases to 1.5 million years. And, when buried 10 meters down, the pumpkin-colored bacterium could survive a whopping 280 million years.

Looking to future missions


This astonishing survival feat is partially thanks to the bacterium's genomic structure, the researchers found. Long suspected, the researchers discovered that Conan the Bacterium's chromosomes and plasmids are linked together, keeping them in perfect alignment and ready for repair after intense radiation.

That means that if a microbe, similar to Conan the Bacterium, evolved during a time when water last flowed on Mars, then its living remains could still be dormant in the deep subsurface.

"Although D. radiodurans buried in the Martian subsurface could not survive dormant for the estimated 2 to 2.5 billion years since flowing water disappeared on Mars, such Martian environments are regularly altered and melted by meteorite impacts," Daly said. "We suggest that periodic melting could allow intermittent repopulation and dispersal. Also, if Martian life ever existed, even if viable lifeforms are not now present on Mars, their macromolecules and viruses would survive much, much longer. That strengthens the probability that, if life ever evolved on Mars, this will be revealed in future missions."

Read more at Science Daily

Biblical military campaigns reconstructed using geomagnetic field data

A joint study by Tel-Aviv University and the Hebrew University, involving 20 researchers from different countries and disciplines, has accurately dated 21 destruction layers at 17 archaeological sites in Israel by reconstructing the direction and/or intensity of the Earth's magnetic field recorded in burnt remnants. The new data verify the Biblical accounts of the Egyptian, Aramean, Assyrian, and Babylonian military campaigns against the Kingdoms of Israel and Judah.

Findings indicate, for example, that the army of Hazael, King of Aram-Damascus, was responsible for the destruction of several cities -- Tel Rehov, Tel Zayit, and Horvat Tevet, in addition to Gath of the Philistines, whose destruction is noted in the Hebrew Bible. At the same time, the study refutes the prevailing theory that Hazael was the conqueror who destroyed Tel Beth-Shean. Other geomagnetic findings reveal that the cities in the Negev were destroyed by the Edomites, who took advantage of the destruction of Jerusalem and the Kingdom of Judah by the Babylonians.

The groundbreaking interdisciplinary study was published in the Proceedings of the National Academy of Sciences (PNAS) and is based on the doctoral thesis of Yoav Vaknin, supervised by Prof. Erez Ben-Yosef and Prof. Oded Lipschits of TAU's Institute of Archaeology and Prof. Ron Shaar from the Institute of Earth Sciences at the Hebrew University.

The researchers explain that geophysicists, attempting to understand the mechanism of earth's magnetic field, track changes in this field throughout history. To this end they use archaeological findings containing magnetic minerals which, when heated or burned, record the magnetic field at the time of the fire. Thus, in a 2020 study, researchers reconstructed the magnetic field as it was on the 9th of the month of Av, 586 BCE, the Hebrew date of the destruction of the First Temple and the City of Jerusalem by Nebuchadnezzar and his Babylonian army. Now, using archaeological findings unearthed over several decades at 17 sites throughout Israel, alongside historical information from ancient inscriptions and Biblical accounts, the researchers were able to reconstruct the magnetic fields recorded in 21 destruction layers. They used the data to develop a reliable new scientific tool for archaeological dating.

Yoav Vaknin explains: "Based on the similarity or difference in intensity and direction of the magnetic field, we can either corroborate or disprove hypotheses claiming that specific sites were burned during the same military campaign. Moreover, we have constructed a variation curve of field intensity over time which can serve as a scientific dating tool, similar to the radiocarbon dating method."

One example given by the researchers is the destruction of Gath of the Philistines (identified today as Tel Tzafit in the Judean foothills) by Hazael, King of Aram-Damascus. Various dating methods have placed this event at around 830 BCE, but were unable to verify that Hazael was also responsible for the destruction of Tel Rehov, Tel Zayit and Horvat Tevet. Now the new study, identifying full statistical synchronization between the magnetic fields recorded at all of these four sites at the time of destruction, makes a very strong case for their destruction during the same campaign. A destruction level at Tel Beth-Shean, on the other hand, recording a totally different magnetic field, refutes the prevailing hypothesis that it too was destroyed by Hazael. Instead, the magnetic data from Beth-Shean indicate that this city, along with two other sites in northern Israel, was probably destroyed 70-100 years earlier, a date which could correspond with the military campaign of the Egyptian Pharaoh Shoshenq. Shoshenq's campaign is described in the Hebrew Bible and in an inscription on a wall of the Temple of Amun in Karnak, Egypt, which mentions Beth-Shean as one of his conquests.

One of the most interesting findings revealed by the new dating method has to do with the end of the Kingdom of Judah. Prof. Erez Ben Yosef: "The last days of the Kingdom of Judah are widely debated. Some researchers, relying on archaeological evidence, argue that Judah was not completely destroyed by the Babylonians. While Jerusalem and frontier cities in the Judean foothills ceased to exist, other towns in the Negev, the southern Judean Mountains and the southern Judean foothills remained almost unaffected. Now, the magnetic results support this hypothesis, indicating that the Babylonians were not solely responsible for Judah's ultimate demise. Several decades after they had destroyed Jerusalem and the First Temple, sites in the Negev, which had survived the Babylonian campaign, were destroyed -- probably by the Edomites who took advantage of the fall of Jerusalem. This betrayal and participation in the destruction of the surviving cities may explain why the Hebrew Bible expresses so much hatred for the Edomites -- for example, in the prophecy of Obadiah."

Prof. Oded Lipschits adds: "The new dating tool is unique because it is based on geomagnetic data from sites, whose exact destruction dates are known from historical sources. By combining precise historical information with advanced, comprehensive archaeological research, we were able to base the magnetic method on reliably anchored chronology."

Read more at Science Daily

Nestling birds recognize their local song 'dialect'

A recent study, published in Current Biology, led by researchers at Stockholm University and Uppsala University, has shown that juvenile songbirds react to hearing the songs they will eventually produce as adults, even when they are as young as 12 days old. Experiments conducted on nestling pied flycatchers across Europe demonstrate that they preferentially respond to songs from their own species and, remarkably, their own population.

Like human children learning language, juvenile songbirds learn their songs by listening to those produced by their parents and other adults. In both human language and songbird song, the learning process gives rise to small changes from one generation to the next, which leads to characteristic differences among populations, called dialects.

Broadcasted songs to nestlings

The study shows that pied flycatcher songs from 7 European populations form clearly defined dialects. By broadcasting songs to almost 2000 nestlings and observing their responses, the researchers demonstrate that young flycatchers respond to songs that are more similar to those from their own dialect by begging for food.

"These results establish that birds are 'tuned' from a young age to recognize their own populations' songs, which focuses subsequent learning," says David Wheatcroft, Associate Professor at the Department of Zoology, Stockholm University, who is the lead author of the study.

How are nestlings able to do this? One possibility is that nestling songbirds listen to their fathers' songs and thereby learn about the local dialect. However, 100s of hours of recordings at flycatcher nests at Stockholm University's Tovetorp Research Station revealed that nestlings hear extremely few songs, and, moreover, that nestlings whose fathers sing most often respond most weakly to the local dialect.

"An alternative is that nestlings recognize their own dialect innately," says David Wheatcroft.

Local dialect helps attract partners

He hopes these results will lead to future studies investigating how these dialect-specific responses develop and their consequences.

"If differences in early song responses among populations are truly innate, it would suggest a remarkable co-evolution between a cultural trait and the genes underlying it. Singing the local dialect is thought to help adults attract appropriate mates."

The researchers also found that dialect-specific responses may help prevent learning the songs of surrounding species. Pied flycatcher nestling responses to the songs of a closely related species, the collared flycatcher, were as weak as those to songs from other pied flycatcher dialects. Thus, the ability to discriminate against the songs of other species arises as a by-product of strong respondes to the local dialect.

Read more at Science Daily

Vocal communication originated over 400 million years ago

The use of vocalizations as a resource for communication is common among several groups of vertebrates: singing birds, croacking frogs, or barking dogs are some well-known examples. These vocalizations play a fundamental role in parental care, mate attraction and various other behaviors. Despite its importance, little is known about when and at what stage in the evolutionary history of vertebrates this behavior first appeared. Comparative analyses can provide insights into the evolutionary origin of acoustic communication, but they are often plagued by missing information from key groups that have not been broadly studied.

Acoustic abilities are widespread in land vertebrates

An international research team led by the University of Zurich (UZH) has therefore focused on species that have never been accessed before. Their study includes evidence for 53 species of four major clades of land vertebrates -- turtles, tuataras, caecilians and lungfishes -- in the form of vocal recordings and contextual behavioral information accompanying sound production. "This, along with a broad literature-based dataset including 1800 different species covering the entire spectrum shows that vocal communication is not only widespread in land vertebrates, but also evidence acoustic abilities in several groups previously considered non-vocal," says first author Gabriel Jorgewich-Cohen, PhD student at the Paleontological Institute and Museum of UZH. Many turtles, for example, which were thought to be mute are in fact showing broad and complex acoustic repertoires.

Last common ancestor lived about 407 million years ago

To investigate the evolutionary origins of acoustic communication in vertebrates, the researchers combined relevant data on the vocalization abilities of species like lizards, snakes, salamanders, amphibians, and dipnoi with phylogenetic trait reconstruction methods. Combined with data of well-known acoustic clades like mammals, birds, and frogs, the researchers were able to map vocal communication in the vertebrate tree of life. "We were able to reconstruct acoustic communication as a shared trait among these animals, which is at least as old as their last common ancestor that lived approximately 407 million years before present," explains Marcelo Sánchez, who led the study.

Read more at Science Daily

Oct 24, 2022

The environmental footprint of food

In an age of industrialized farming and complex supply chains, the true environmental pressures of our global food system are often obscure and difficult to assess.

"Everyone eats food, and more and more people are paying attention to the planetary consequences of what they eat," said UC Santa Barbara marine ecologist Ben Halpern. Figuring out this impact to the planet proves to be a gargantuan task for many reasons, including the fact that around the world there are a lot of different foods produced in many different ways, with many different environmental pressures.

By ranking foods on factors such as greenhouse gas emissions or water pollution, scientists have made useful headway on assessments of the environmental impacts of food by pound or kilogram. While these evaluations are helpful in guiding consumer choices, Halpern explained that a more comprehensive examination of the environmental footprint -- the locations affected by the various pressures from food production and the severity of that pressure -- is needed for decisions that have to be made in a world with a booming population.

"The individual choice of eight billion people adds up," he said, "and we need to know the overall impact of total food production -- not just per pound -- especially when setting food policy."

To fill that need, Halpern and colleagues at UC Santa Barbara's National Center for Ecological Analysis & Synthesis (NCEAS) have mapped for the first time the environmental footprint of the production of all foods, both in the ocean and on land. Their research is published in the journal Nature Sustainability.

Lopsided pressures and hidden connections

"Did you know that almost half of all environmental pressures from food production come from just five countries?" Halpern said.

For Halpern, executive director at NCEAS and a professor at UCSB's Bren School of Environmental Science & Management, understanding the impacts of food production along with the local context of these impacts has been a longstanding interest. By taking detailed data about greenhouse gas emissions, freshwater use, habitat disturbance and nutrient pollution (e.g., fertilizer runoff) generated by 99% of total reported production of aquatic and terrestrial foods in 2017, and mapping those impacts at high resolution, the researchers were able to create a more nuanced picture of the pressures -- the inputs, processes and outputs -- of global food production.

The findings are eye-opening.

"Cumulative pressures of food production are more concentrated than previously believed, with the vast majority -- 92% of pressures from land-based food production -- concentrated on just 10% of the Earth's surface," noted Melanie Frazier, a research scientist at NCEAS and coauthor of the paper. Additionally, the space required for dairy and beef farming accounts for about a quarter of the cumulative footprint of all food production. And those five countries accounting for almost half of all food production-related environmental pressures? India, China, the United States, Brazil and Pakistan.

The study also examines the environmental efficiency of each food type, similar to the per-pound of food approach that most other studies use, but now accounting for differences among countries rather than just assuming it is the same everywhere.

"The environmental efficiency of producing a particular food type varies spatially, such that rankings of foods by efficiency differ sharply among countries, and this matters for guiding which foods we eat and from where," said Halley Froehlich, assistant professor in environmental studies at UCSB and a coauthor of the study.

Methods of production factor into the research team's assessment. For instance, thanks to technology that reduces greenhouse gases and increases yields, the United States -- the world's number one producer of soy -- is more than twice as efficient as India (the fifth largest producer) at producing the crop, making American soy the more environmentally friendly choice.

The research also uncovers connections between land and sea that get missed when looking only at one or the other, and that result in significant environmental pressures. Pigs and chicken have an ocean footprint because marine forage fish such as herrings, anchovies and sardines are used for their feed. The converse is true for mariculture farms, whose crop-based feeds extend the fish farms' environmental pressure on to land.

Assessing cumulative pressures can bring to light results that could not have been predicted by examining individual pressures alone. For instance, while raising cattle requires by far the most grazing land, the cumulative pressures of pig farming, which produces a lot of pollution and uses more water than cattle farming, are slightly greater than that of cows. Measured by cumulative pressures, the top five offenders are pig, cow, rice, wheat and oil crops.

In order to feed a growing and increasingly wealthy global population while reducing environmental degradation and enhancing food security, major shifts will need to be made to current food systems, according to the researchers. In some cases, farming might need to improve efficiency; in other cases, consumers might need to change their food choices.

"We need this comprehensive information to make more accurate decisions about what we eat," said Halpern, who modified his own food choices based on the results of this study.

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Skaftö wreck's cargo tells a tale of 15th century trade routes

Research at the University of Gothenburg has shown that the Skaftö wreck had probably taken on cargo in Gdańsk in Poland and was heading towards Belgium when it foundered in the Lysekil archipelago around 1440. Modern methods of analysis of the cargo are now providing completely new answers about the way trade was conducted in the Middle Ages.

"The analyses we have carried out give us a very detailed picture of the ship's last journey and also tell us about the geographical origins of its cargo. Much of this is completely new knowledge for us," says Staffan von Arbin, a maritime archaeologist.

For example, it was not previously known that calcium oxide (CaO), commonly known as quicklime or burnt lime, was exported from Gotland in the 15th century.

In 2003, the Skaftö wreck was found at the bottom of the sea off Lysekil, north of Gothenburg. But it is only now that researchers have been able to carry out analyses of its cargo using new, modern methods.

An international research team, headed by maritime archaeologist Staffan von Arbin at the University of Gothenburg, has succeeded in mapping the origins of its cargo and the probable route of the ship. The study contributes new knowledge about the goods traded in the Middle Ages and the trade routes in that period.

The cargo included copper, oak timber, quicklime, tar, and bricks and roof tiles. Samples of the cargo have been taken up from the wreck during previous underwater archaeological investigations carried out by the Bohusläns museum. But it's only now that analyses of its cargo have been possible using modern analysis methods.

From Gotland in Sweden

With these analyses, the researchers have been able to establish that the copper was mined in two areas in what is currently Slovakia, for example. The analyses also show that the bricks, timber and probably also the tar originated in Poland, while the quicklime is apparently from Gotland.

According to medieval sources, copper was transported from the Slovakian mining districts in the Carpathian Mountains via river systems down to the coastal town of Gdańsk (Danzig) in Poland. In the Middle Ages, Gdańsk was also the dominant port for exporting Polish oak timber.

"It is therefore very likely that it was in Gdańsk that the ship took on its cargo before it continued on what would be its final voyage."

Heading for Belgium

The composition of the cargo indicates that the ship was on its way to a western European port when, for unknown reasons, it foundered in the Bohuslän archipelago. Here, too, the research team have drawn conclusions from historical sources.

"We believe that the ship's final destination was Bruges in Belgium. In the 15th century, this city was a major trading hub. We also know that copper produced in Central Europe was shipped on from there to various Mediterranean ports, including Venice."

The study presents the recent investigations of the composition of the cargo. These results were then compared with other sources from the same period, archaeological as well as historical. The study has been published in the article Tracing Trade Routes: Examining the Cargo of the 15th-Century Skaftö Wreck, in the International Journal of Nautical Archaeology.

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UK's oldest human DNA obtained, revealing two distinct Palaeolithic populations

The first genetic data from Palaeolithic human individuals in the UK -- the oldest human DNA obtained from the British Isles so far -- indicates the presence of two distinct groups that migrated to Britain at the end of the last ice age, according to new research.

Published today in Nature Ecology and Evolution, the new study by UCL Institute of Archaeology, the Natural History Museum and the Francis Crick Institute researchers reveals for the first time that the recolonisation of Britain consisted of at least two groups with distinct origins and cultures.

The study team explored DNA evidence from an individual from Gough's Cave, Somerset, and an individual from Kendrick's Cave, North Wales, who both lived more than 13,500 years ago. Very few skeletons of this age exist in Britain, with around a dozen found across six sites in total. The study, which involved radiocarbon dating and analysis as well as DNA extraction and sequencing, shows that it is possible to obtain useful genetic information from some of the oldest human skeletal material in the country.

The authors say that these genome sequences now represent the earliest chapter of the genetic history of Britain, but ancient DNA and proteins promise to take us back even further into human history.

The researchers found that the DNA from the individual from Gough's Cave, who died about 15,000 years ago, indicates that her ancestors were part of an initial migration into northwest Europe around 16,000 years ago. However, the individual from Kendrick's Cave is from a later period, around 13,500 years ago, with his ancestry from a western hunter-gatherer group. This group's ancestral origins are thought to be from the near East, migrating to Britain around 14,000 years ago.

Study co-author Dr Mateja Hajdinjak (Francis Crick Institute) said: "Finding the two ancestries so close in time in Britain, only a millennium or so apart, is adding to the emerging picture of Palaeolithic Europe, which is one of a changing and dynamic population."

The authors note that these migrations occurred after the last ice age when approximately two-thirds of Britain was covered by glaciers. As the climate warmed and the glaciers melted, drastic ecological and environmental changes took place and humans began to move back into northern Europe.

Study co-author Dr Sophy Charlton, who undertook the study whilst at the Natural History Museum, said: "The period we were interested in, from 20-10,000 years ago, is part of the Palaeolithic -- the Old Stone Age. This is an important time period for the environment in Britain, as there would have been significant climate warming, increases in the amount of forest, and changes in the type of animals available to hunt."

As well as genetically, the two groups were found to be culturally distinct, with differences in what they ate and how they buried their dead.

Study co-author Dr Rhiannon Stevens (UCL Institute of Archaeology) said: "Chemical analyses of the bones showed that the individuals from Kendrick's Cave ate a lot of marine and freshwater foods, including large marine mammals.

"Humans at Gough's Cave, however, showed no evidence of eating marine and freshwater foods, and primarily ate terrestrial herbivores such as red deer, bovids (such as wild cattle called aurochs) and horses."

The researchers discovered that the mortuary practices of the two groups also differed. Although there were animal bones found at Kendrick's Cave, these included portable art items, such as a decorated horse jawbone. No animal bones were found that showed evidence of being eaten by humans, and the scientists say that this indicates the cave was used as a burial site by its occupiers.

In contrast, animal and human bones found in Gough's Cave showed significant human modification, including human skulls modified into 'skull-cups', which the researchers believe to be evidence for ritualistic cannibalism. Individuals from this earlier population seem to be the same people who created the Magdalenian stone tools, a culture known also for iconic cave art and bone artefacts.

Gough's Cave is also the site where Britain's famous Cheddar Man was discovered in 1903, dated to 10,564-9,915 years BP. In this study, Cheddar Man was found to have a mixture of ancestries, mostly (85%) western hunter-gatherer and some (15%) of the older type from the initial migration.

Co-author Dr Selina Brace (Natural History Museum) said: "We really wanted to find out more about who these early populations in Britain might have been.

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Video gaming may be associated with better cognitive performance in children, study suggests

A study of nearly 2,000 children found that those who reported playing video games for three hours per day or more performed better on cognitive skills tests involving impulse control and working memory compared to children who had never played video games. Published today in JAMA Network Open, this study analyzed data from the ongoing Adolescent Brain Cognitive Development (ABCD) Study, which is supported by the National Institute on Drug Abuse (NIDA) and other entities of the National Institutes of Health.

"This study adds to our growing understanding of the associations between playing video games and brain development," said NIDA Director Nora Volkow, M.D. "Numerous studies have linked video gaming to behavior and mental health problems. This study suggests that there may also be cognitive benefits associated with this popular pastime, which are worthy of further investigation."

Although a number of studies have investigated the relationship between video gaming and cognitive behavior, the neurobiological mechanisms underlying the associations are not well understood. Only a handful of neuroimaging studies have addressed this topic, and the sample sizes for those studies have been small, with fewer than 80 participants.

To address this research gap, scientists at the University of Vermont, Burlington, analyzed data obtained when children entered the ABCD Study at ages 9 and 10 years old. The research team examined survey, cognitive, and brain imaging data from nearly 2,000 participants from within the bigger study cohort. They separated these children into two groups, those who reported playing no video games at all and those who reported playing video games for three hours per day or more. This threshold was selected as it exceeds the American Academy of Pediatrics screen time guidelines, which recommend that videogaming time be limited to one to two hours per day for older children. For each group, the investigators evaluated the children's performance on two tasks that reflected their ability to control impulsive behavior and to memorize information, as well as the children's brain activity while performing the tasks.

The researchers found that the children who reported playing video games for three or more hours per day were faster and more accurate on both cognitive tasks than those who never played. They also observed that the differences in cognitive function observed between the two groups was accompanied by differences in brain activity. Functional MRI brain imaging analyses found that children who played video games for three or more hours per day showed higher brain activity in regions of the brain associated with attention and memory than did those who never played. At the same time, those children who played at least three hours of videogames per day showed more brain activity in frontal brain regions that are associated with more cognitively demanding tasks and less brain activity in brain regions related to vision.

The researchers think these patterns may stem from practicing tasks related to impulse control and memory while playing videogames, which can be cognitively demanding, and that these changes may lead to improved performance on related tasks. Furthermore, the comparatively low activity in visual areas among children who reported playing video games may reflect that this area of the brain may become more efficient at visual processing as a result of repeated practice through video games.

While prior studies have reported associations between video gaming and increases in depression, violence, and aggressive behavior, this study did not find that to be the case. Though children who reported playing video games for three or more hours per day did tend to report higher mental health and behavioral issues compared to children who played no video games, the researchers found that this association was not statistically significant, meaning that the authors could not rule out whether this trend reflected a true association or chance. They note that this will be an important measure to continue to track and understand as the children mature.

Further, the researchers stress that this cross-sectional study does not allow for cause-and-effect analyses, and that it could be that children who are good at these types of cognitive tasks may choose to play video games. The authors also emphasize that their findings do not mean that children should spend unlimited time on their computers, mobile phones, or TVs, and that the outcomes likely depend largely on the specific activities children engage in. For instance, they hypothesize that the specific genre of video games, such as action-adventure, puzzle solving, sports, or shooting games, may have different effects for neurocognitive development, and this level of specificity on the type of video game played was not assessed by the study.

"While we cannot say whether playing video games regularly caused superior neurocognitive performance, it is an encouraging finding, and one that we must continue to investigate in these children as they transition into adolescence and young adulthood," said Bader Chaarani, Ph.D., assistant professor of psychiatry at the University of Vermont and the lead author on the study. "Many parents today are concerned about the effects of video games on their children's health and development, and as these games continue to proliferate among young people, it is crucial that we better understand both the positive and negative impact that such games may have."

Through the ABCD Study, researchers will be able to conduct similar analyses for the same children over time into early adulthood, to see if changes in video gaming behavior are linked to changes in cognitive skills, brain activity, behavior, and mental health. The longitudinal study design and comprehensive data set will also enable them to better account for various other factors in the children's families and environment that may influence their cognitive and behavioral development, such as exercise, sleep quality, and other influences.

The ABCD Study, the largest of its kind in the United States, is tracking nearly 12,000 youth as they grow into young adults. Investigators regularly measure participants' brain structure and activity using magnetic resonance imaging (MRI) and collect psychological, environmental, and cognitive information, as well as biological samples. The goal of the study is to understand the factors that influence brain, cognitive, and social-emotional development, to inform the development of interventions to enhance a young person's life trajectory.

Read more at Science Daily

Oct 23, 2022

Looking to move to a galaxy far, far away? Innovative system evaluates habitability of distant planets

The climate crisis presents a huge challenge to all people on Earth. It has led many scientists to look for exoplanets, planets outside our solar system that humans could potentially settle.

The James Webb Space Telescope was developed as part of this search to provide detailed observational data about Earth-like exoplanets in the coming years. A new project, led by Dr. Assaf Hochman at the Fredy & Nadine Herrmann Institute of Earth Sciences at the Hebrew University of Jerusalem (HU), in collaboration with Dr. Paolo De Luca at the Barcelona Supercomputing Center and Dr. Thaddeus D. Komacek at the University of Maryland, has successfully developed a framework to study the atmospheres of distant planets and locate those planets fit for human habitation, without having to visit them physically. Their joint research study was published in the Astrophysical Journal.

Classifying climate conditions and measuring climate sensitivity are central elements when assessing the viability of exoplanets as potential candidates for human habitation. In the current study, the research team examined TRAPPIST-1e, a planet located some 40 light years from the Earth and scheduled to be documented by the James Webb Space Telescope in the coming year. The researchers looked at the sensitivity of the planet's climate to increases in greenhouse gases and compared it with conditions on Earth. Using a computerized simulation of the climate on TRAPPIST-1e, they could assess the impact of changes in greenhouse gas concentration.

The study focused on the effect of an increase in carbon dioxide on extreme weather conditions, and on the rate of changes in weather on the planet. "These two variables are crucial for the existence of life on other planets, and they are now being studied in depth for the first time in history," explained Hochman.

According to the research team, studying the climate variability of earth-like exoplanets provides a better understanding of the climate changes we are currently experiencing on Earth. Additionally, this kind of research offers a new understanding of how planet Earth's atmosphere might change in the future.

Hochman and his research partners found that planet TRAPPIST-1e has a significantly more sensitive atmosphere than planet Earth. They estimate that an increase in greenhouse gases there could lead to more extreme climate changes than we would experience here on Earth because one side of TRAPPIST-1e constantly faces its own sun, in the same way, that our moon always has one side facing the Earth.

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