Lightest black hole or heaviest neutron star? MeerKAT uncovers a mysterious object in Milky Way

An international team of astronomers have found a new and unknown object in the Milky Way that is heavier than the heaviest neutron stars known and yet simultaneously lighter than the lightest black holes known.

Using the MeerKAT Radio Telescope, astronomers from a number of institutions including The University of Manchester and the Max Planck Institute for Radio Astronomy in Germany found an object in orbit around a rapidly spinning millisecond pulsarlocated around 40,000 light years away in a dense group of stars known as a globular cluster.

Using the clock-like ticks from the millisecond pulsar they showed that the massive object lies in the so-called black hole mass gap.

It could be the first discovery of the much-coveted radio pulsar -- black hole binary; a stellar pairing that could allow new tests of Einstein's general relativity and open doors to the study of black holes.

The results are published today in the journal Science.

UK project lead Ben Stappers, Professor of Astrophysics at The University of Manchester, said: "Either possibility for the nature of the companion is exciting. A pulsar-black hole system will be an important target for testing theories of gravity and a heavy neutron star will provide new insights in nuclear physics at very high densities."

When a neutron star -- the ultra-dense remains of dead star -- acquire too much mass, usually by consuming or colliding with another star, they will collapse. What they become after they collapse is the cause of much speculation, but it is believed that they could become black holes -- objects so gravitationally attractive that even light cannot escape them.

Astronomers believe that the total mass required for a neutron star to collapse is 2.2 times the mass of the sun. Theory, backed by observation, tells us that the lightest black holes created by these stars are much larger, at about five times more massive than the Sun, giving rise to what is known as the 'black hole mass gap'.

The nature of compact objects in this mass gap is unknown and detailed study has so far proved challenging. The discovery of the object may help finally understand these objects.

Prof Stappers, added: "The ability of the extremely sensitive MeerKAT telescope to reveal and study these objects is a enabling a great step forward and provides us with a glimpse of what will be possible with the Square Kilometre Array."

The discovery of the object was made while observing a large cluster of stars known as NGC 1851 located in the southern constellation of Columba, using the MeerKAT telescope.

The globular cluster NGC 1851 is a dense collection of old stars that are much more tightly packed than the stars in the rest of the Galaxy. Here, it is so crowded that the stars can interact with each other, disrupting orbits and in the most extreme cases colliding.

The astronomers, part of the international Transients and Pulsars with MeerKAT (TRAPUM) collaboration, believe that it is one such collision between two neutron stars that is proposed to have created the massive object that now orbits the radio pulsar.

The team were able to detect faint pulses from one of the stars, identifying it as a radio pulsar -- a type of neutron star that spins rapidly and shines beams of radio light into the Universe like a cosmic lighthouse.

The pulsar spins more than 170 times a second, with every rotation producing a rhythmic pulse, like the ticking of a clock. The ticking of these pulses is incredibly regular and by observing how the times of the ticks change, using a technique called pulsar timing, they were able to make extremely precise measurements of its orbital motion.

Ewan Barr from Max Planck Institute for Radio Astronomy, who led the study with his colleague Arunima Dutta, explained: "Think of it like being able to drop an almost perfect stopwatch into orbit around a star almost 40,000 light years away and then being able to time those orbits with microsecond precision."

The regular timing also allowed a very precise measurement of the system's location, showing that the object in orbit with the pulsar was no regular star but an extremely dense remnant of a collapsed star. Observations also showed that the companion has a mass that was simultaneously bigger than that of any known neutron star and yet smaller than that of any known black hole, placing it squarely in the black-hole mass gap.

While the team cannot conclusively say whether they have discovered the most massive neutron star known, the lightest black hole known or even some new exotic star variant, what is certain is that they have uncovered a unique laboratory for probing the properties of matter under the most extreme conditions in the Universe.

Arunima Dutta concludes: "We're not done with this system yet.

Read more at Science Daily

Paper provides a clearer picture of severe hydro hazards

Over the last two decades an estimated three billion people have been affected by water-related natural disasters such as droughts and floods. Climate change is expected to increase the frequency of these hydro hazards, with some prognosticators estimating there will be upwards of $3.7 trillion in water-related damage over the next 30 years in the U.S. alone. Beyond damaging homes and infrastructure, severe wet and dry spells will also devastate crops and deplete water reservoirs.

An increasing area of interest to researchers is the frequency of compound drought and pluvial flooding (caused by quick, heavy rainfall or sustained rainfall beyond the norm), which is when both occur in succession in the same area within a year of each other.

Historically, this level of coincidence has been under-examined.

Of similar interest is when the reverse happens: extreme rainfall followed by a meteorological drought.

Meteorological drought is when dry weather patterns prevail, which can eventually trigger hydrological drought, leading to dry streams and plunging reservoir levels, such as what happened at Lake Mead in 2022.

A new study co-authored by researchers in the University of Arkansas Department of Geosciences, as well as colleagues in China, now provides a global examination of drought-pluvial volatility -- or the tendency to shift from one extreme to another (from dry to wet or wet to dry) in a short period of time.

Yichan Li, a Ph.D. candidate at the U of A, was the first of four authors on the paper, "Observational Uncertainty for Global Drought-Pluvial Volatility," published in Water Resources Research, while Linyin Cheng, an assistant professor of geosciences, was second author.

The study looks at extreme dry-to-wet and wet-to-dry transitions over the past seven decades through event coincidence analysis, a method of quantifying the number of consecutive extreme events that also considers instantaneous or lagged responses within an uncertain period between them.

The study used three widely used climate data sets to provide evidence of increased drought-pluvial volatility on time scales of less than a year.

The team also evaluated the accuracy of these data sets, finding varying strengths and weaknesses of each due to observational uncertainties in data collection.

For instance, the remoteness of a region may play a role in collecting accurate data.

Averaged out at the global scale, the team found that 15.46% of all meteorological droughts were succeeded by a pluvial the following season.

The wet-to-dry transition percentage proved remarkably similar: 15.49%. However, prominent differences exist when looking at particular regions.

Toward that end, the study provides a map demonstrating how incidents of these two phenomena are distributed globally.

Overall, the spatial pattern of extreme dry-to-wet and wet-to-dry events' coincidence rates is largely in agreement among the three data sets, though there is prominent regional variability.

For instance, in Eurasia since the mid-20th century, there is a relatively low probability for meteorological droughts transitioning to pluvials, but a higher chance for the opposite scenario, rapid shifts from wet to dry events.

A similar pattern also exists over western North America, which sees severe wet to dry transitions at a frequency greater than 17% on average.

Conversely, South Asia and Australia are more prone to immediate transitions from meteorological droughts to pluvials.

The authors noted: "Our findings indicate that differences associated with drought-pluvial volatility among the considered observations are in many regions larger than that of their single events [droughts or pluvials alone], highlighting a need of to use multiple independent observation-based data sets for more robust examinations when studying such compound extreme events."

Ultimately, the authors stress the need to use multiple independent observation-based data sets when analyzing extreme, compound dry-to-wet events.

This will provide clearer guidelines for climate-related decision making, especially water resources planning, as well as ensure better accuracy when modeling future weather events.

Read more at Science Daily

New video camera system captures the colored world that animals see, in motion

A new camera system allows ecologists and filmmakers to produce videos that accurately replicate the colors that different animals see in natural settings, Vera Vasas at the University of Sussex, UK, and colleagues from the Hanley Color Lab at George Mason University, US, report in the open access journal PLOS Biology, publishing January 23rd.

Different animals perceive the world differently because of the capabilities of the photoreceptors in their eyes.

For example, animals like honeybees and some birds can see UV light, which are outside the range of human perception.

Reconstructing the colors that animals actually see can help scientists better understand how they communicate and navigate the world around them.

False color images give us a glimpse into this dynamic world, but traditional methods such as spectrophotometry are often time consuming, require specific lighting conditions, and cannot capture moving images.

To address these limitations, researchers developed a novel camera and software system that captures animal-view videos of moving objects under natural lighting conditions.

The camera simultaneously records video in four color channels: blue, green, red and UV. This data can be processed into "perceptual units" to produce an accurate video of how those colors are perceived by animals, based on existing knowledge of the photoreceptors in their eyes.

The team tested the system against a traditional method that uses spectrophotometry and found that the new system predicted perceived colors with an accuracy of over 92%.

This novel camera system will open new avenues of research for scientists, and allow filmmakers to produce dynamic, accurate depictions of how animals see the world around them, the authors say.

The system is built from commercially available cameras, housed in a modular, 3D-printed casing, and the software is available open-source, allowing other researchers to use and build on the technology in the future.

Read more at Science Daily

The fountain of youth is ... a T cell?

The fountain of youth has eluded explorers for ages. It turns out the magic anti-aging elixir might have been inside us all along.

Cold Spring Harbor Laboratory (CSHL) Assistant Professor Corina Amor Vegas and colleagues have discovered that T cells can be reprogrammed to fight aging, so to speak.

Given the right set of genetic modifications, these white blood cells can attack another group of cells known as senescent cells.

These cells are thought to be responsible for many of the diseases we grapple with later in life.

Senescent cells are those that stop replicating. As we age, they build up in our bodies, resulting in harmful inflammation.

While several drugs currently exist that can eliminate these cells, many must be taken repeatedly over time.

As an alternative, Amor Vegas and colleagues turned to a "living" drug called CAR (chimeric antigen receptor) T cells.

They discovered CAR T cells could be manipulated to eliminate senescent cells in mice.

As a result, the mice ended up living healthier lives. They had lower body weight, improved metabolism and glucose tolerance, and increased physical activity.

All benefits came without any tissue damage or toxicity.

"If we give it to aged mice, they rejuvenate. If we give it to young mice, they age slower. No other therapy right now can do this, " says Amor Vegas.

Perhaps the greatest power of CAR T cells is their longevity.

The team found that just one dose at a young age can have lifelong effects.

That single treatment can protect against conditions that commonly occur later in life, like obesity and diabetes.

"T cells have the ability to develop memory and persist in your body for really long periods, which is very different from a chemical drug, " explains Amor Vegas.

"With CAR T cells, you have the potential of getting this one treatment, and then that's it. For chronic pathologies, that's a huge advantage. Think about patients who need treatment multiple times per day versus you get an infusion, and then you're good to go for multiple years."

CAR T cells have been used to treat a variety of blood cancers, receiving FDA approval for this purpose in 2017.

But Amor Vegas is one of the first scientists to show that CAR T cells' medical potential goes even further than cancer.

Read more at Science Daily

Atmospheric pressure changes could be driving Mars' elusive methane pulses

New research shows that atmospheric pressure fluctuations that pull gases up from underground could be responsible for releasing subsurface methane into Mars' atmosphere; knowing when and where to look for methane can help the Curiosity rover search for signs of life.

"Understanding Mars' methane variations has been highlighted by NASA's Curiosity team as the next key step towards figuring out where it comes from," said John Ortiz, a graduate student at Los Alamos National Laboratory who led the research team.

"There are several challenges associated with meeting that goal, and a big one is knowing what time of a given sol (Martian day) is best for Curiosity to perform an atmospheric sampling experiment."

The paper was published the week of Jan. 22 in the Journal of Geophysical Research: Planets.

A primary focus of NASA's Mars missions, including Curiosity and Perseverance, is to detect and understand past or present signs of life, such as methane.

However, with the source of methane on Mars likely being underground, short-term variations in atmospheric methane levels have posed a research challenge.

To better understand Mars' methane levels, Ortiz and his team used high-performance computing clusters to simulate how methane travels through networks of underground fractures and is released into the atmosphere, where it then mixes within the atmospheric column.

They also modeled how methane is adsorbed onto the pores of rocks, which is a temperature-dependent process that may contribute to the methane level fluctuations.

Their simulations predicted methane pulses from the ground surface into the atmosphere just before the Martian sunrise in the planet's northern summer season, which just recently ended.

This corroborates previous rover data suggesting that methane levels fluctuated not only seasonally, but also daily.

This valuable data is helping inform the Curiosity rover's ongoing sampling campaign.

Read more at Science Daily

Complex green organisms emerged a billion years ago

Of all the organisms that photosynthesize, land plants have the most complex bodies. How did this morphology emerge? A team of scientists led by the University of Göttingen has taken a deep dive into the evolutionary history of morphological complexity in streptophytes, which include land plants and many green algae. Their research allowed them to go back in time to investigate lineages that emerged long before land plants existed. Their results revise the understanding of the relationships of a group of filamentous algal land colonizers much older than land plants. Using modern gene sequencing data, researchers pinpoint the emergence of multicellularity to almost a billion years ago. The results were published in the journal Current Biology.

The study focused on Klebsormidiophyceae, a class of green algae known for its ability to colonize diverse habitats worldwide.

The team of researchers conducted extensive sampling, investigating habitats ranging from streams, rivers, and lake shores to bogs, soil, natural rocks, tree bark, acidic post-mining sites, sand dunes, urban walls, and building façades.

"It's really fascinating that these tiny robust little organisms have such a high diversity in their morphology and also are extremely well adapted to live in sometimes very harsh environments," says Dr Tatyana Darienko, University of Göttingen's Institute for Microbiology and Genetics.

This comprehensive sampling aimed to create a global distribution map for Klebsormidiophyceae, emphasizing their adaptability, ecological significance, and hidden diversity.

Based on genetic data calibrated by fossils, the researchers performed "molecular clock analyses."

While delving into the complex evolutionary history of Klebsormidiophyceae, the researchers faced challenges in resolving phylogenetic relationships using traditional markers.

To overcome this, they employed hundreds of genes obtained from the transcriptomes of 24 isolates from different continents and habitats.

"Our approach, known as phylogenomics, was to reconstruct the evolutionary history taking into account whole genomes or large fractions of genomes," explains Dr Iker Irisarri, Leibniz Institute for the Analysis of Biodiversity Change.

"This extremely powerful method can reconstruct evolutionary relationships with very high precision."

Read more at Science Daily

Global groundwater depletion is accelerating, but is not inevitable

Groundwater is rapidly declining across the globe, often at accelerating rates. Writing in the journal Nature, UC Santa Barbara researchers present the largest assessment of groundwater levels around the world, spanning nearly 1,700 aquifers. In addition to raising the alarm over declining water resources, the work offers instructive examples of where things are going well, and how groundwater depletion can be solved. The study is a boon for scientists, policy makers and resource managers working to understand global groundwater dynamics.

"This study was driven by curiosity. We wanted to better understand the state of global groundwater by wrangling millions of groundwater level measurements," said lead author Debra Perrone, an associate professor in UC Santa Barbara's Environmental Studies Program.

The team compiled data from national and subnational records and the work of other agencies. The study took three years, two of which were spent just cleaning and sorting data. That's what it takes to make sense of 300 million water level measurements from 1.5 million wells over the past 100 years.

Next came the task of translating the deluge of data into actual insights about global groundwater trends. The researchers then scoured over 1,200 publications to reconstruct aquifer boundaries in the regions of inquiry and evaluate groundwater level trends in 1,693 aquifers.

Their findings provide the most comprehensive analysis of global groundwater levels to date, and demonstrate the prevalence of groundwater depletion. The work revealed that groundwater is dropping in 71% of the aquifers. And this depletion is accelerating in many places: the rates of groundwater decline in the 1980s and '90s sped up from 2000 to the present, highlighting how a bad problem became even worse. The accelerating declines are occurring in nearly three times as many places as they would expect by chance.

Groundwater deepening is more common in drier climates, with accelerated decline especially prevalent in arid and semi-arid lands under cultivation -- "an intuitive finding," said co-lead author Scott Jasechko, an associate professor in the university's Bren School of Environmental Science & Management. "But it's one thing for something to be intuitive. It's quite another to show that it's happening with real-world data."

On the other hand, there are places where levels have stabilized or recovered. Groundwater declines of the 1980s and '90s reversed in 16% of the aquifer systems the authors had historical data for. However, these cases are only half as common as would be expected by chance.

"This study shows that humans can turn things around with deliberate, concentrated efforts," Jasechko said.

Take Tucson, Arizona for instance. Water allotted from the Colorado River is used to replenish the aquifer in the nearby Avra Valley. The project stores water for future use. "Groundwater is often viewed as a bank account for water," Jasechko explained. "Intentionally refilling aquifers allows us to store that water until a time of need."

Communities can spend a lot of money building infrastructure to hold water above ground. But if you have the right geology, you can store vast quantities of water underground, which is much cheaper, less disruptive and less dangerous. The stored groundwater can also benefit the region's ecology. In fact, while preparing a research brief in 2014, Perrone found that aquifer recharge can store six times more water per dollar than surface reservoirs.

Tucson's groundwater recharge is a boon for the local aquifer; however, withdrawals have caused the mighty river to dwindle above ground. The Colorado rarely reaches its delta in the California Gulf anymore. "These groundwater interventions can have tradeoffs," Jasechko acknowledged.

Another option is to focus on reducing demand. Often this involves regulations, permitting and fees for groundwater use, Perrone explained. To this end, she is currently examining water law in the western U.S. to understand these diverse interventions. Regardless of whether it comes from supply or demand, aquifer recovery seemed to require intervention, the study revealed.

The authors complemented measurements from monitoring wells with data from the Gravity Recovery and Climate Experiment (GRACE). The GRACE mission consists of twin satellites that precisely measure the distance between them as they orbit the Earth. In this way, the crafts detect small fluctuations in the planet's gravity, which can reveal the dynamics of aquifers at large scales.

"The beauty of GRACE is that it allows us to explore groundwater conditions where we don't have in-situ data," Perrone said. "Our assessment complements GRACE. Where we do have in-situ data, we can explore groundwater conditions locally, a crucial level of resolution when you're managing depletion." This local resolution is critical, as the authors found out, because adjacent aquifers can display different trends.

That said, groundwater level trends don't present the whole picture. Even where aquifers remain stable, withdrawing groundwater can still affect nearby streams and surface water, causing them to leak into the subsurface, as Perrone and Jasechko detailed in another Nature paper in 2021.

The authors also analyzed precipitation variability over the past four decades for 542 aquifers. They found that 90% of aquifers where declines were accelerating are in places where conditions have gotten drier over the last 40 years. These trends have likely reduced groundwater recharge and increased demand. On the other hand, climate variability can also enable groundwater to rebound where conditions become wetter.

This study of monitoring wells complements a paper Perrone and Jasechko released in 2021. That study represented the largest assessment of global groundwater wells, and made the cover of the journal Science. "The monitoring wells are telling us information about supply. And the groundwater wells are telling us information about demand," Perrone said.

"Taken together, they allow us to understand which wells have run dry already, or are most likely to run dry if groundwater-level declines occur," Jasechko added.

Perrone and Jasechko are now examining how groundwater levels vary over time in the context of climate change. Connecting these rates of change to the depths of actual wells will provide better predictions of where groundwater access is at risk.

Read more at Science Daily

World's first successful embryo transfer in rhinos paves the way for saving the northern white rhinos from extinction

BioRescue, an international consortium of scientists and conservationists, succeeded in achieving the world's first pregnancy of a rhinoceros after an embryo transfer. The southern white rhino embryo was produced in vitro from collected egg cells and sperm and transferred into a southern white rhino surrogate mother at the Ol Pejeta Conservancy in Kenya on September 24, 2023. The BioRescue team confirmed a pregnancy of 70 days with a well-developed 6.4 cm long male embryo. The successful embryo transfer and pregnancy are a proof of concept and allow to now safely move to the transfer of northern white rhino embryos -- a cornerstone in the mission to save the northern white rhino from extinction.

On September 24, 2023, the BioRescue scientists and veterinarians, led by the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW), transferred two southern white rhino embryos into Curra, a southern white rhinoceros, selected as a surrogate mother at the Ol Pejeta Conservancy in Kenya. The oocytes used in producing the embryos were retrieved from Elenore, a southern white rhinoceros living in the Pairi Daiza Zoo in Belgium. The sperm used for fertilisation originated from the male Athos from the Zoo Salzburg in Hellbrunn, Austria. The oocytes from Elenore were fertilised in vitro by intracytoplasmic sperm injection (ICSI) and developed into blastoscysts at Avantea's laboratories in Cremona, Italy. For the embryo transfer in Kenya, the BioRescue scientists transferred two embryos to increase the chance of a successful outcome.

So far, the BioRescue team has performed 13 embryo transfers in rhinoceroses, three in Kenya and ten in Europe. Previously, an embryo transfer, which is a widely used technique in domestic species, has never been attempted in rhinos. BioRescue scientists developed the necessary techniques, by building on decades of their own research.

Currently, there are only two northern white rhinos left in the world: The female Najin and her daughter Fatu. Additionally, living cells from 12 different northern white rhino individuals are stored in liquid nitrogen. The last two females currently live in Kenya, at Ol Pejeta Conservancy, where they are guarded and cared for day and night. Since 2019, the BioRescue conservation science programme produced and cryopreserved 30 northern white rhino embryos. These are currently stored in liquid nitrogen at minus 196 degrees Celsius in Berlin, Germany, and Cremona, Italy, awaiting embryo transfer into southern white rhino surrogate mothers. The successful transfer of a southern white rhino embryo is a proof of concept that allows to take this crucial step -- an embryo transfer with a northern white rhino embryo -- for the first time.

The embryo transfer in this subspecies is entirely new ground as a veterinary and scientific procedure, and all protocols, methods and pieces of equipment had to be newly developed from scratch. As it is the established routine with all BioRescue procedures, the embryo transfers are accompanied by an ethical assessment conducted by Padua University. This was also the case in September, when all participants of the embryo transfer filled out a questionnaire that proposed any possible scenarios during the procedure, and attendant risks to animals and participants.

The vasectomised, sterile teaser bull Ouwan mated with Curra on September 17 and 18, signalling the ideal timing for the embryo transfer, which took place on September 24. After the procedure until November 2023, Curra was monitored on a daily basis in the enclosure at the Ol Pejeta Conservancy. During this period, Ouwan showed no further interest in Curra, a first sign of a successful embryo transfer resulting in pregnancy. The BioRescue team was scheduled for November 28 to perform a pregnancy check in Curra, but the teaser bull Ouwan was found dead on November 22 and Curra was found dead on November 25. Apparently, extremely heavy rains led to a flooding of the surrogate enclosure and set free dormant clostridianbacteria spores. The dissection of the animals revealed a severe systemic infection by a clostridian bacterial strain and resultant intoxication by the bacterial toxin. It also revealed that Curra was pregnant with a 70 days old male fetus that was 6.4 cm long. Tissue samples of the fetus were collected and transported to the Max Delbrück Centre for Molecular Medicine and the Leibniz-IZW in Berlin, Germany. In January 2024, it was confirmed through the analysis of the fetus DNA that the pregnancy resulted from the embryo transfer.

When the BioRescue team arrived in Kenya on November 28, the preliminary results indicated an intoxication with the clostridian bacterial strains Paraclostridium bifermentans and Paenicolostridium sordellii. Immediately after the incident, the BioRescue team, including Kenya Wildlife Service, Wildlife Training Research Institute, Ol Pejeta Conservancy and Safari Park Dvur Králové formed a crisis team on site and established fast and effective measures to protect all current semi-captive rhinos including the last two northern white rhinos Najin and Fatu. The measures included a vaccination programme, quarantine of affected areas and fencing of new emergency enclosures.

The next steps in the BioRescue research programme included the selection and preparation of a new teaser bull. The bull will allow the scientists to know when a possible surrogate female is ready to receive an embryo implantation. The team also has to select the next surrogate mothers. After these steps, which will take several months, an embryo transfer with a northern white rhino embryo will be attempted.

Read more at Science Daily

Records of cometary dust hitting the asteroid Ryugu

Ryugu is a near-Earth asteroid that gained significant attention when the Japanese Hayabusa2 mission collected samples and returned them to Earth. These samples have proven to offer a treasure trove of insights into the solar systems, including the possible role of asteroids in delivering organic molecules to earth.

Now, a team of scientists have performed an intensive investigation of Ryugu samples, discovering evidence that points to cometary organic matter being transported from space to the near-Earth region.

The team included Megumi Matsumoto, an assistant professor from the Earth Science Department at Tohoku University Graduate School of Science.

Details of their findings were published in the journal Science Advances on January 19, 2024.

Asteroid Ryugu has no protective atmospheres, and its surface layer is directly exposed to space.

Small interplanetary dust in space can hit the asteroid surface, causing changes to the composition of the asteroid surface materials.

Matsumoto and her colleagues revealed that the sample surfaces contain small 'melt splashes,' ranging in size from 5 to 20 micrometers.

These melt splashes were created when micrometeoroids of cometary dust bombarded Ryugu.

"Our 3D CT imaging and chemical analyses showed that the melt splashes consist mainly of silicate glasses with voids and small inclusions of spherical iron sulfides," says Matsumoto.

"The chemical compositions of the melt splashes suggest that Ryugu's hydrous silicates mixed with cometary dust."

The mixing and melting of Ryugu's surface materials and cometary dust during impact induced heating and rapid cooling formed the melt splashes.

The voids correspond to the water vapor released from the Ryugu's hydrous silicates and subsequently captured in the melt splashes.

Analysis also revealed small carbonaceous materials with abundant nano-pores and iron sulfide inclusions in the melt splashes.

The carbonaceous materials are texturally similar to primitive organic matter in cometary dust, though they lack nitrogen and oxygen, making them chemically different from organic matter.

"We propose that the carbonaceous materials formed from cometary organic matter via the evaporation of volatiles, such as nitrogen and oxygen, during the impact-induced heating. This suggests that cometary matter was transported to the near-Earth region from the outer solar system," adds Matsumoto.

"This organic matter might be the small seeds of life once delivered from space to Earth."

Read more at Science Daily

A new perspective on the temperature inside tropical forests

New worldwide maps of temperatures inside tropical forests show that global warming affect different way in different parts of the forests. Undergrowth level temperature of the tropical forests can be even 4 degrees less than average temperature of the area.

Tropical forests host up to half of the planet's biodiversity but up to now, ecological studies over tropical forests often relied on large scale datasets depicting open-air temperatures -- that is, the temperature outside the forests, which can be several degrees different from the temperatures inside the forest.

This limitation imposed a large barrier in our understanding on how species will respond to climate change.

The research coordinated at the University of Helsinki and the Finnish Meteorological Institute by associate professor Eduardo Maeda, has now achieved a major step to overcome this limitation.

The results have been published in the scientific journal Nature communication.

Hotspots of microclimate refugia

Temperature is a fundamental factor defining the survival, growth, and reproduction rate of species living inside tropical forests.

New study provides maps of temperature inside forests that can be used by ecologists to massively improve the reliability of species distribution models.

"The maps will help to predict with higher confidence how species will respond to climate change, such as to where species are more likely to migrate," says Maeda.

Furthermore, we are able to identify hotspots of microclimate refugia (i.e., areas that can maintain stable and cool microclimates). These areas are likely to be more and more important in a warming future -- with highly detailed maps provided by this study, we can now indicate to policy makers where these areas are, so they can be more efficiently preserved.

Building on an extensive international collaboration effort, the researchers compiled data from hundreds of temperature sensors installed inside tropical forests across the world.

The study also used satellite data that provided information on different characteristics of the forests, such as the height of the trees and the leaf density.

All this information were combined in a machine learning algorithm that was able to estimate temperatures inside tropical forests throughout the entire planet.

The result of this study demonstrates an amazing variability in the temperatures experienced inside forests, which were not visible from other available datasets.

For example, the differences between temperatures inside and outside forests are larger in regions with a distinct dry season (e.g., in southern Amazon forest). Areas with lower rainfall are usually associated with higher temperatures, but this study demonstrate that the deep roots of tropical trees can still access water reserves, thus maintaining their 'airconditioning' function in the ecosystem.

"We already knew that temperatures inside forest differ substantially from those outside forests. Our study shows that those differences are evident not only in terms of magnitude (ie., the absolute difference between temperature inside and outside forest) but also in terms of spatial and temporal heterogeneity," says Maeda.

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Student discovers 200-million-year-old flying reptile

Gliding winged-reptiles were amongst the ancient crocodile residents of the Mendip Hills in Somerset, researchers at the University of Bristol have revealed.

Kuehneosaurs looked like lizards, but were more closely related to the ancestors of crocodilians and dinosaurs.

They were small animals, which could fit neatly on the palm of a hand, and there were two species, one with extensive wings, the other with shorter wings, made from a layer of skin stretched over their elongated side ribs, which allowed them to swoop from tree to tree.

Like the modern flying lizard Draco from southeast Asia, they most likely wandered about on the ground and climbed trees in search of insect prey.

When startled, or if they spotted a tasty insect flying by, they could launch themselves into the air, and land safely 10m away.

The discovery was made by University of Bristol Masters student Mike Cawthorne, researching numerous reptile fossils from limestone quarries, which formed the biggest sub-tropical island at the time, called the Mendip Palaeo-island.

The study, published today in Proceedings of the Geologists' Association, also records the presence of reptiles with complex teeth, the trilophosaur Variodens and the aquatic Pachystropheus that probably lived a bit like a modern-day otter likely eating shrimps and small fish.

The animals either fell or their bones were washed into caves and cracks in the limestone.

"All the beasts were small," said Mike.

"The collections I studied had been made in the 1940s and 1950s when the quarries were still active, and palaeontologists were able to visit and see fresh rock faces and speak to the quarrymen."

Professor Mike Benton Bristol's School of Earth Sciences explained: "It took a lot of work identifying the fossil bones, most of which were separate and not in a skeleton.

"However, we have a lot of comparative material, and Mike Cawthorne was able to compare the isolated jaws and other bones with more complete specimens from the other sites around Bristol.

"He has shown that the Mendip Palaeo-island, which extended from Frome in the east to Weston-super-Mare in the west, nearly 30 km long, was home to diverse small reptiles feeding on the plants and insects.

"He didn't find any dinosaur bones, but it's likely that they were there because we have found dinosaur bones in other locations of the same geological age around Bristol."

The area around Bristol 200 million years ago in the Late Triassic was an archipelago of small islands set in a warm sub-tropical sea.

Bristol's Dr David Whiteside added: "The bones were collected by some great fossil finders in the 1940s and 1950s including Tom Fry, an amateur collector working for Bristol University and who generally cycled to the quarries and returned laden with heavy bags of rocks.

Read more at Science Daily

Shallow soda lakes show promise as cradles of life on Earth

Charles Darwin proposed that life could have emerged in a "warm little pond" with the right cocktail of chemicals and energy. A study from the University of Washington, published this month in Communications Earth & Environment, reports that a shallow "soda lake" in western Canada shows promise for matching those requirements. The findings provide new support that life could have emerged from lakes on the early Earth, roughly 4 billion years ago.

Scientists have known that under the right conditions, the complex molecules of life can emerge spontaneously. As recently fictionalized in the blockbuster hit "Lessons in Chemistry," biological molecules can be coaxed to form from inorganic molecules. In fact, long after the real-life 1950s-era discovery made amino acids, the building blocks of proteins, more recent work has made the building blocks of RNA. But this next step requires extremely high phosphate concentrations.

Phosphate forms the "backbone" of RNA and DNA and is also a key component of cell membranes. The concentrations of phosphate required to form these biomolecules in the lab are hundreds to 1 million times higher than the levels normally found in rivers, lakes or in the ocean. This has been called the "phosphate problem" for the emergence of life -- a problem that soda lakes may have solved.

"I think these soda lakes provide an answer to the phosphate problem," said senior author David Catling, a UW professor of Earth and space sciences. "Our answer is hopeful: This environment should occur on the early Earth, and probably on other planets, because it's just a natural outcome of the way that planetary surfaces are made and how water chemistry works."

Soda lakes get their name from having high levels of dissolved sodium and carbonate, similar to dissolved baking soda. This occurs from the reactions between water and volcanic rocks beneath. Soda lakes can also have high levels of dissolved phosphate.

Previous UW research in 2019 found that chemical conditions for life to emerge could theoretically occur in soda lakes. The researchers combined chemical models with laboratory experiments to show that natural processes can theoretically concentrate phosphate in these lakes to levels up to 1 million times higher than in typical waters.

For the new study, the team set out to study such an environment on Earth. By coincidence, the most promising candidate was within driving distance. Tucked away at the end of a master's thesis from the 1990s was the highest known natural phosphate level in the scientific literature at Last Chance Lake in inland British Columbia, Canada, about seven hours' drive from Seattle.

The lake is about 1 foot deep and has murky water with fluctuating levels. It sits on federal land at the end of a dusty dirt road on the Cariboo Plateau, in British Columbia ranching country. The shallow lake meets the requirements for a soda lake: a lake above volcanic rock (in this case, basalt) combined with a dry, windy atmosphere that evaporates incoming water to keep water levels low and concentrates dissolved compounds within the lake.

Analysis published in the new paper suggests soda lakes are a strong candidate for the emergence of life on Earth. They also could be a candidate for life on other planets.

"We studied a natural environment that should be common throughout the solar system. Volcanic rocks are prevalent on the surfaces of planets, so this same water chemistry could have occurred not just on early Earth, but also on early Mars and early Venus, if liquid water was present," said lead author Sebastian Haas, a UW postdoctoral researcher in Earth and space sciences.

The UW team visited Last Chance Lake three times from 2021 to 2022. They collected observations in early winter, when the lake was covered in ice; in early summer, when rain-fed springs and snowmelt-fed streams put water at its highest; and in late summer when the lake had almost completely dried up.

"You have this seemingly dry salt flat, but there are nooks and crannies. And between the salt and the sediment there are little pockets of water that are really high in dissolved phosphate," Haas said. "What we wanted to understand was why and when could this happen on the ancient Earth, in order to provide a cradle for the origin of life."

On all three visits the team collected samples of water, lake sediment and salt crust to understand the lake's chemistry.

In most lakes the dissolved phosphate quickly combines with calcium to form calcium phosphate, the insoluble material that makes up our tooth enamel. This removes phosphate from the water. But in Last Chance Lake, calcium combines with plentiful carbonate as well as magnesium to form dolomite, the same mineral that forms picturesque mountain ranges. This reaction was predicted by the previous modeling work and confirmed when dolomite was plentiful in Last Chance Lake's sediments. When calcium turns into dolomite and does not remain in the water, the phosphate lacks a bonding partner -- and so its concentration rises.

"This study adds to growing evidence that evaporative soda lakes are environments meeting the requirements for origin-of-life chemistry by accumulating key ingredients at high concentrations," Catling said.

The study also compared Last Chance Lake with Goodenough Lake, a roughly 3-foot-deep lake with clearer water and different chemistry just a two-minute walk away, to learn what makes Last Chance Lake unique. The researchers wondered why life, present in all modern lakes at some level, was not using up the phosphate in Last Chance Lake.

Goodenough Lake has mats of cyanobacteria that extract or "fix" nitrogen gas from the air. Cyanobacteria, like all other lifeforms, also require phosphate -- and its growing population consumes some of that lake water's phosphate supply. But Last Chance Lake is so salty that it inhibits living things that do the energy-intensive work of fixing atmospheric nitrogen. Last Chance Lake harbors some algae but has insufficient available nitrogen to host more life, allowing phosphate to accumulate. This also makes it a better analog for a lifeless Earth.

"These new findings will help inform origin-of-life researchers who are either replicating these reactions in the lab or are looking for potentially habitable environments on other planets," Catling said.

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The metalens meets the stars

Metalenses have been used to image microscopic features of tissue and resolve details smaller than a wavelength of light. Now they are going bigger.

Researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have developed a 10-centimeter-diameter glass metalens that can image the sun, the moon and distant nebulae with high resolution.

It is the first all-glass, large-scale metalens in the visible wavelength that can be mass produced using conventional CMOS fabrication technology.

The research is published in ACS Nano.

"The ability to accurately control the size of tens of billions of nanopillars over an unprecedentedly large flat lens using state-of-the-art semiconductor foundry processes is a nanofabrication feat that opens exciting new opportunities for space science and technology," said Federico Capasso, the Robert L. Wallace Professor of Applied Physics and Vinton Hayes Senior Research Fellow in Electrical Engineering at SEAS and senior author of the paper.

Most flat metalenses, which use millions of pillar-like nanostructures to focus light, are about the size of a piece of glitter.

In 2019, Capasso and his team developed a centimeter-scale metalens using a technique called deep-ultraviolet (DUV) projection lithography,which projects and forms a nanostructure pattern that can be directly etched into the glass wafer, eliminating the time-consuming writing and deposition processes that were required for previous metalenses.

DUV projection lithography is commonly used to pattern fine lines and shapes in silicon chips for smartphones and computers.

Joon-Suh Park, a former graduate student at SEAS and current postdoctoral fellow in Capasso's team, demonstrated that the technique could not only be used to mass produce metalenses but also increase their size for applications in virtual and augmented reality.

But making the metalens even larger for applications in astronomy and free-space optical communications posed an engineering problem.

"There is a major limitation with the lithography tool because these tools are used to make computer chips, so chip size is restricted to no more than 20 to 30 millimeters," said Park, co-first author of the paper.

"In order to make a 100-millimeter diameter lens, we needed to find a way around this limitation."

Park and the team developed a technique to stitch together several patterns of nanopillars using the DUV projection lithography tool.

By dividing the lens into 25 sections but using only the 7 sections of a quadrant considering the rotational symmetry, the researchers showed that DUV projection lithography could pattern 18.7 billion designed nanostructures onto a 10-centimeter circular area in a matter of minutes.

The team also developed a vertical glass etching technique that allows the creation of high-aspect ratio, smooth-sidewall nanopillars etched into glass.

"Using the same DUV projection lithography, one could produce large-diameter, aberration-correcting meta-optics or even larger lenses on larger glass diameter wafers as the corresponding CMOS foundry tools become increasingly available in the industry," said Soon Wei Daniel Lim, a postdoctoral fellow at SEAS and co-first author of the paper.

Lim played a lead role in the full simulation and characterization of all the possible fabrication errors that could arise during mass-manufacturing processes and how they could impact the optical performance of metalenses.

After addressing possible manufacturing challenges, the researchers demonstrated the power of the metalens in imaging celestial objects.

Mounting the metalens on a tripod with a color filter and camera sensor, Park and the team took to the roof of Harvard's Science Center.

There, they imaged the Sun, the moon and the North America nebula, a dim nebula in the constellation Cygnus about 2,590 light years away.

"We were able to get very detailed images of the Sun, the moon and the nebula that are comparable to images taken by conventional lenses" said Arman Amirzhan, a graduate student in the Capasso Lab and co-author of the paper.

Using only the metalens, the researchers were able to image the same cluster of sunspots as a NASA image taken that same day.

The team also demonstrated that the lens could survive exposure to extreme heat, extreme cold and the intense vibrations that would occur during a space launch without any damage or loss in optical performance.

Because of its size and monolithic glass composition, the lens could also be used for long-range telecommunications and directed energy transport applications.

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Ice age could help predict oceans' response to global warming

A team of scientists led by a Tulane University oceanographer has found that deposits deep under the ocean floor reveal a way to measure the ocean oxygen level and its connections with carbon dioxide in the Earth's atmosphere during the last ice age, which ended more than 11,000 years ago.

The findings, published in Science Advances, help explain the role oceans played in past glacial melting cycles and could improve predictions of how ocean carbon cycles will respond to global warming.

Oceans adjust atmospheric CO2 as ice ages transition to warmer climates by releasing the greenhouse gas from carbon stored within the deep ocean.

The research demonstrates a striking correlation between global ocean oxygen contents and atmospheric CO2 from the last ice age to today -- and how carbon release from the deep sea may rise as the climate warms.

"The research reveals the important role of the Southern Ocean in controlling the global ocean oxygen reservoir and carbon storage," said Yi Wang, lead researcher and an assistant professor of Earth and Environmental Sciences at Tulane University School of Science and Engineering.

Wang specializes in marine biogeochemistry and paleoceanography.

"This will have implications for understanding how the ocean, especially the Southern Ocean, will dynamically affect the atmospheric CO2 in the future," she said.

Wang conducted the study with colleagues from the Woods Hole Oceanographic Institution, the world's leading independent nonprofit organization dedicated to ocean research, exploration and education.

She worked for the institute before joining Tulane in 2023.

The team analyzed seafloor sediments collected from the Arabian Sea to reconstruct average global ocean oxygen levels thousands of years ago.

They precisely measured isotopes of the metal thallium trapped in the sediments, which indicate how much oxygen was dissolved in the global ocean at the time the sediments formed.

"Study of these metal isotopes on glacial-interglacial transitions has never been looked at before, and these measurements allowed us to essentially recreate the past," Wang said.

The thallium isotope ratios showed the global ocean lost oxygen overall during the last ice age compared to the current warmer interglacial period.

Their study revealed thousand-year global ocean deoxygenation during abrupt warming in the Northern Hemisphere, whereas the ocean gained more oxygen when abrupt cooling occurred during the transition from the last ice age to today.

The researchers attributed the observed ocean oxygen changes to Southern Ocean processes.

"This study is the first to present an average picture of how the oxygen content of the global oceans evolved as Earth transitioned from the last glacial period into the warmer climate of the last 10,000 years," said Sune Nielsen, associate scientist at WHOI and co-author of the research.

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The megalodon was less mega than previously believed

A new study shows the Megalodon, a gigantic shark that went extinct 3.6 million years ago, was more slender than earlier studies suggested. This finding changes scientists’ understanding of Megalodon behavior, ancient ocean life, and why the sharks went extinct.

The Megalodon or megatooth shark is typically portrayed as a super-sized monster in popular culture, with recent examples in the sci-fi films “The Meg” (2018) and “Meg 2: The Trench” (2023). Previous studies assume that the shark likely reached lengths of at least 50 feet and possibly as much as 65 feet.

However, the Megalodon is largely known only from its teeth and vertebrae in the fossil record — a rather incomplete set of data from which to draw assumptions.

Thus, the modern great white shark was traditionally used as a model for Megalodon bodies in previous studies.

That model led researchers to conclude that the shark was round and stocky like great whites.

“Our team reexamined the fossil record, and discovered the Megalodon was more slender and possibly even longer than we thought. Therefore, a better model might be the modern mako shark,” said UCR biologist and paper first author Phillip Sternes.

“It still would have been a formidable predator at the top of the ancient marine food chain, but it would have behaved differently based on this new understanding of its body.”

For the new study published in the journal Palaeontologia Electronica, a team of 26 scientists from around the world, co-led by Sternes and DePaul University paleobiology professor Kenshu Shimada, was inspired by differences in previously estimated body lengths for the Megalodon.

“It was a ‘eureka-moment’ when our research team realized the discrepancy between two previously published lengths for the same Megalodon specimen,” said Shimada.

The team then weighed in on a new comparison of Megalodon vertebra fossils to those of living lamniform shark relatives.

“We measured the whole vertebral skeleton of a living great white shark with a CT scanner and compared that to the previous reconstruction of the Megalodon vertebral column,” Sternes said.

“It was still a giant, predatory shark. But the results strongly suggest that the Megalodon was not merely a larger version of the modern great white shark.”

A revised understanding of the Megalodon body type would in turn affect scientists’ understanding not only of the giant shark itself, but also of its impact on the ecology and evolution of marine ecosystems that shaped the present-day oceans.

There is no doubt the Megalodon is one of the largest marine predators ever to have lived.

But a slimmer and more elongated body would suggest the Megalodon also had a longer digestive canal.

Sternes explained that in this case, the sharks might have enjoyed enhanced absorption of nutrients, and may not have had to eat as often as previously believed.

“With increased ability to digest its food, it could have gone for longer without needing to hunt. This means less predation pressure on other marine creatures,” Sternes said.

“If I only have to eat one whale every so often, whale populations would remain more stable over time.”

Some shark scientists have theorized that a natural decrease in prey led to the extinction of Megalodons.

However, Sternes has another theory, in part supported by the revised understanding of its shape.

“I believe there were a combination of factors that led to the extinction, but one of them may have been the emergence of the great white shark, which was possibly more agile, making it an even better predator than the Megalodon,” Sternes said.

“That competition for food may have been a major factor in its demise.”

The research team of shark experts from the U.S., UK, Austria, France, Japan, Mexico, Brazil, and Australia all feel that a revised understanding of ancient marine life would have a cascading effect on the oceans that are still visible today.

Read more at Science Daily

New medicine can create a new life for diabetes patients -- without needles!

There are approximately 425 million people worldwide with diabetes. Approximately 75 million of these inject themselves with insulin daily. Now they may soon have a new alternative to syringes or insulin pumps. Scientists have found a new way to supply the body with smart insulin.

The new insulin can be eaten by taking a capsule or even better, within a piece chocolate.

Inside these we find tiny nano-carriers to which the insulin is encapsulated. The particles are 1/10,000th the width of a human hair and so small that you cannot even see them under a normal microscope.

"This way of taking insulin is more precise because it delivers the insulin rapidly to the areas of the body that need it most. When you take insulin with a syringe, it is spread throughout the body where it can cause unwanted side effects," explains Professor Peter McCourt at UiT Norway's Arctic University. He is one of the researchers behind the study.

The research was recently published in Nature Nanotechnology.

Delivered to the liver

It was researchers at the University of Sydney and Sydney Local Health District who, in collaboration with UiT, discovered many years ago that it was possible to deliver medicines via nano-carriers to the liver. The method has then been further developed in Australia and in Europe.

Many medicines can be taken by mouth, but until now people have had to inject insulin into the body. McCourt explains that the problem with insulin with a nano-carrier is that it breaks down in the stomach and thus does not get to where it is needed in the body. This has been a major challenge for developing a diabetes medicine that can be taken orally.

But now the researchers have solved this challenge.

"We have created a coating to protect the insulin from being broken down by stomach acid and digestive enzymes on its way through the digestive system, keeping it safe until it reaches its destination, namely the liver," says McCourt, who is a liver biologist.

The coating is then broken down in the liver by enzymes that are active only when the blood sugar levels are high, releasing the insulin where it can then act in the liver, muscle, and fat to remove sugar from the blood.

"This means that when blood sugar is high, there is a rapid release of insulin, and even more importantly, when blood sugar is low, no insulin is released," says Nicholas J. Hunt at the University of Sydney who, together with Victoria Cogger, leads the project.

He explains that this is a more practical and patient-friendly method of managing diabetes because it greatly reduces the risk of a low blood sugar event occurring, namely hypoglycemia and allows for the controlled released of insulin depending on the patient's needs, unlike injections where all the insulin is released in one shot.

Fewer side effects

The new method works similarly to how insulin works in healthy people. The pancreas produces insulin which first passes through the liver where a large portion of it is absorbed and maintains stable blood sugar levels. In the new insulin method, the nano-carrier releases insulin in the liver, where it can be taken up or enter the blood to circulate in the body.

"When you inject insulin under the skin with a syringe, far more of it goes to the muscles and to adipose tissues that would normally happen if it was released from the pancreas, which can lead to the accumulation of fats. It can also lead to hypoglycemia, which can potentially be dangerous for people with diabetes.

With the new method, there will be fewer such side effects.

In addition, you do not need to stab yourself with a needle and you can take the medicine you need in a slightly more discreet way. Also, this form of insulin does not need to be refrigerated.

Tested on baboons

The oral insulin has been tested on nematodes, on mice and rats. And lastly, the medicine has now been tested on baboons in the National Baboon Colony in Australia.

"In order to make the oral insulin palatable we incorporated it into sugar-free chocolate, this approach was well received" says Hunt.

He says that 20 baboons have taken part in this study. When they received the medicine, their blood sugar was lowered.

The baboons were normal, healthy baboons, but the oral insulin have also been tested on mice and rats that actually have diabetes. The mice and rats did not have low blood sugar events (hypoglycemia), gain weight or fat accumulation in the liver overcoming current challenges with injectable and other oral insulins.

What remains now is to test the new method on humans.

Ready for use in 2-3 years

"Trials on humans will start in 2025 led by the spin out company Endo Axiom Pty Ltd. Clinical trials are performed in 3 phases; in the phase I trial we will investigate the safety of the oral insulin and critically look at the incidence of hypoglycemia in healthy and type 1 diabetic patients. Our team is very excited to see if we can reproduce the absent hypoglycemia results seen in baboons in humans as this would be a huge step forward. The experiments follow strict quality requirements and must be carried out in collaboration with physicians to ensure that they are safe for the test subjects" says Hunt.

Read more at Science Daily

Origin of intense light in supermassive black holes and tidal disruption events revealed

Anew study by Hebrew University is a significant breakthrough in understanding Tidal Disruption Events (TDEs) involving supermassive black holes. The new simulations, for the first time ever, accurately replicate the entire sequence of a TDE from stellar disruption to the peak luminosity of the resulting flare. This study has unveiled a previously unknown type of shockwave within TDEs, settling a longstanding debate about the energy source of the brightest phases in these events. It confirms that shock dissipation powers the brightest weeks of a TDE flare, opening doors for future studies to utilize TDE observations as a means to measure essential properties of black holes and potentially test Einstein's predictions in extreme gravitational environments.

The mysteries of supermassive black holes have long captivated astronomers, offering a glimpse into the deepest corners of our universe.

Now, a new study led by Dr. Elad Steinberg and Dr. Nicholas C. Stone at the Racah Institute of Physics, The Hebrew University, sheds new light on these enigmatic cosmic entities.

Supermassive black holes, ranging from millions to billions of times the mass of our Sun, have remained elusive despite their pivotal role in shaping galaxies.

Their extreme gravitational pull warps spacetime, creating an environment that defies conventional understanding and presents a challenge for observational astronomers.

Enter Tidal Disruption Events (TDEs), a dramatic phenomenon that occurs when ill-fated stars venture too close to a black hole's event horizon, and are torn apart into thin streams of plasma.

As this plasma returns towards the black hole, a series of shockwaves heat it up, leading to an extraordinary display of luminosity -- a flare that surpasses the collective brightness of an entire galaxy for weeks or even months.

The study conducted by Steinberg and Stone represents a significant leap forward in understanding these cosmic events.

For the first time, their simulations have recreated a realistic TDE, capturing the complete sequence from the initial star disruption to the peak of the ensuing luminous flare, all made possible by pioneering radiation-hydrodynamics simulation software developed by Steinberg at The Hebrew University.

This research has uncovered a previously unexplored type of shockwave within TDEs, revealing that these events dissipate their energy at a faster rate than previously understood.

By clarifying this aspect, the study resolves a long-standing theoretical debate, confirming that the brightest phases of a TDE flare are powered by shock dissipation -- a revelation that sets the stage for comprehensive exploration by observational astronomers.

These findings pave the way for translating TDE observations into precise measurements of crucial black hole properties, including mass and spin.

Moreover, these cosmic occurrences could serve as a litmus test for validating Einstein's predictions in extreme gravitational environments.

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Next-generation batteries could go organic, cobalt-free for long-lasting power

In the switch to "greener" energy sources, the demand for rechargeable lithium-ion batteries is surging. However, their cathodes typically contain cobalt -- a metal whose extraction has high environmental and societal costs. Now, researchers in ACS Central Science report evaluating an earth-abundant, carbon-based cathode material that could replace cobalt and other scarce and toxic metals without sacrificing lithium-ion battery performance.

Today, lithium-ion batteries power everything from cell phones to laptops to electric vehicles.

One of the limiting factors for realizing a global shift to energy produced by renewable sources -- particularly for the transition from gasoline-powered cars to electric vehicles -- is the scarcity and mining difficulty of the metals, such as cobalt, nickel and magnesium, used in rechargeable battery cathode manufacturing.

Previous researchers have developed cathodes from more abundant and lower cost carbon-containing materials, including organosulfur and carbonyl compounds, but those prototypes couldn't match the energy output and stability of traditional lithium-ion batteries.

So, Mircea Dincǎ and his colleagues wanted to see if other carbon-based cathode materials could be more successful.

They may have found a worthy candidate in bis-tetraaminobenzoquinone (TAQ). TAQ molecules form layered solid-state structures than can potentially compete with traditional cobalt-based cathode performance.

Building on their prior work that showed TAQ's effectiveness as a supercapacitor material, Dincǎ's team tested the compound in a cathode for lithium-ion batteries. To improve cycling stability and to increase TAQ adhesion to the cathode's stainless-steel current collector, they added cellulose- and rubber-containing materials to the TAQ cathode. In the researchers' proof-of-concept demonstration, the new composite cathode cycled safely more than 2,000 times, delivered an energy density higher than most cobalt-based cathodes and charged-discharged in as little as six minutes. The TAQ-based cathodes need additional testing before they appear on the market, but the researchers are optimistic that they could enable the high-energy, long-lasting and fast-charging batteries needed to help speed a global transition to a renewable energy future that's cobalt- and nickel-free.

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Sea otters helped prevent widespread California kelp forest declines over the past century

Monterey Bay Aquarium researchers strengthen the link between sea otters and long-term health of California kelp forests in a new study released today. The paper, published in the journal PLOS Climate, finds that sea otter population growth during the last century enhanced kelp forest resilience in the state. This finding reinforces the importance of conservation and recovery of the threatened southern sea otter and highlights a potential nature-based solution for restoring kelp forests along the California coast, and perhaps beyond.

The study revealed dramatic regional kelp canopy changes over a 100-year period, from 1910 to 2016.

During this time there was a significant increase in kelp forest canopy along the central coast, the only region of California where southern sea otters survived after being hunted nearly to extinction for their fur in the 1800s.

At the century scale, the species' favorable impact on kelp forests along the central coast nearly compensated for kelp losses along both northern and southern California resulting in a slight overall decline statewide during this period.

"Our study showed that kelp forests are more extensive and resilient to climate change where sea otters have reoccupied the California coastline during the last century. Where sea otters are absent, kelp forests have declined dramatically. In fact, we found sea otter population density as the strongest predictor of change in kelp canopy coverage across this hundred-year span," said lead author Teri Nicholson, Senior Research Biologist with the Monterey Bay Aquarium Sea Otter Program.

Aquarium scientists used historical surveys of kelp forests dating back to the early 1900s to perform detailed estimates of canopy extent, biomass, and carbon storage -- while correcting for annual variation and differences in survey methods.

This allowed the scientists to examine California's kelp forest trends over a longer time period, going back more than 60 years before available data from modern surveys based on aerial or satellite imagery.

The team then compared the corrected and conservative historical estimates to contemporary datasets and used a machine learning framework to assess the dominant drivers of change over the last century.

"The use of historical maps provided an important opportunity to help us examine long-term kelp forest trends," said Monterey Bay Aquarium Sea Otter Program Manager, Jess Fujii.

"This broader view is important for understanding trends related to climate change, and developing effective science-based conservation strategies."

Statewide, the data showed only a six percent decline in kelp canopy from 1910 to 2016.

Regional changes, however, proved more sizable. Kelp canopy decreased in northern and southern regions by 63 and 52 percent, respectively.

It increased nearly everywhere throughout the central coast, contrastingly, gaining an estimated 56 percent of kelp forest coverage.

While the modeling showed sea otter population density was the strongest predictor of change in kelp coverage, it also identified other factors, including extreme marine heat due to climate change.

"Today, extreme heat in the ocean is intense and persistent. Beginning a decade ago, this threat now affects more than half the ocean's surface," said Kyle Van Houtan, a Research Scientist at Duke University, and senior author of the study.

"This is a major problem for kelp forests as chronic temperature stress undermines kelp growth and health. Ecosystems are complex, and to give them their best chance at surviving these extreme changes, they need all their component parts. Sea otters, of course, are hugely influential for Pacific kelp forests. Historical studies like this are a crucial demonstration of this dynamic over the long term."

Read more at Science Daily