Astronomers detect most distant fast radio burst to date

An international team has spotted a remote blast of cosmic radio waves lasting less than a millisecond. This 'fast radio burst' (FRB) is the most distant ever detected. Its source was pinned down by the European Southern Observatory's (ESO) Very Large Telescope (VLT) in a galaxy so far away that its light took eight billion years to reach us. The FRB is also one of the most energetic ever observed; in a tiny fraction of a second it released the equivalent of our Sun's total emission over 30 years.

The discovery of the burst, named FRB 20220610A, was made in June last year by the ASKAP radio telescope in Australia and it smashed the team's previous distance record by 50 percent.

"Using ASKAP's array of dishes, we were able to determine precisely where the burst came from," says Stuart Ryder, an astronomer from Macquarie University in Australia and the co-lead author of the study published today in Science. "Then we used [ESO's VLT] in Chile to search for the source galaxy, finding it to be older and further away than any other FRB source found to date and likely within a small group of merging galaxies."

The discovery confirms that FRBs can be used to measure the 'missing' matter between galaxies, providing a new way to 'weigh' the Universe.

Current methods of estimating the mass of the Universe are giving conflicting answers and challenging the standard model of cosmology. "If we count up the amount of normal matter in the Universe -- the atoms that we are all made of -- we find that more than half of what should be there today is missing," says Ryan Shannon, a professor at the Swinburne University of Technology in Australia, who also co-led the study. "We think that the missing matter is hiding in the space between galaxies, but it may just be so hot and diffuse that it's impossible to see using normal techniques."

"Fast radio bursts sense this ionised material. Even in space that is nearly perfectly empty they can 'see' all the electrons, and that allows us to measure how much stuff is between the galaxies," Shannon says.

Finding distant FRBs is key to accurately measuring the Universe's missing matter, as shown by the late Australian astronomer Jean-Pierre ('J-P') Macquart in 2020. "J-P showed that the further away a fast radio burst is, the more diffuse gas it reveals between the galaxies. This is now known as the Macquart relation. Some recent fast radio bursts appeared to break this relationship. Our measurements confirm the Macquart relation holds out to beyond half the known Universe," says Ryder.

"While we still don't know what causes these massive bursts of energy, the paper confirms that fast radio bursts are common events in the cosmos and that we will be able to use them to detect matter between galaxies, and better understand the structure of the Universe," says Shannon.

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Urgent action needed to address climate change threats to coastal areas

Global coastal adaptations are 'incremental in scale', short-sighted and inadequate to address the root causes of vulnerability to climate change, according to an international team of researchers.

The 17 experts, including Prof Robert Nicholls, Professor of Climate Adaptation at the University of East Anglia (UEA), have contributed to the paper, 'Status of global coastal adaptation', which is published today in Nature Climate Change.

Prof Nicholls said: "Recent analyses conclude that despite adaptation undertaken in all regions and sectors, global action remains incremental in scale: policies and projects are usually short-sighted and single hazard-focused, inadequately address the root causes of exposure and vulnerability, and are poorly monitored. There is also little evidence of effective risk reduction in relation to implemented responses."

To address these problems, the experts say decisive action by the international policy community is needed to identify and tackle global priorities in key risk areas across countries.

Dr Alexandre Magnan, of the Institute for Sustainable Development and International Relations (IDDRI), is first author of the paper.

Dr Magnan said: "Assessing climate adaptation is a burning scientific and policy question because, as today's global climate risk will experience a two- to four-fold increase by the end of this century depending on the global greenhouse gas emissions trajectory, we need to know the current status toward addressing its consequences.

"New, alternative methods to assess adaptation are urgently needed in order carry out effective planning and action, evidence on risk reduction, capabilities and create a long-term vision."

The paper considered 61 coastal case studies to develop a locally informed perspective on the state of global coastal adaptation. It looked at both extreme events and low-onset climate change, including coastal erosion, marine flooding, sea-level rise and extremes, soil and groundwater salinization, inland flooding resulting from heavy precipitations, and permafrost thaw.

While strategies for urban coastal areas are generally more advanced than rural ones, the experts said plans for long-term adaptations remain limited.

The experts concluded that today's global coastal adaptation is half-way to the full adaptation potential.

Taking sea-level rise as one example, the experts said the risks to low-lying coasts are already detectable.

Prof Nicholls said: "By the end of the century and in the absence of ambitious adaptation efforts, these risks will become significant, widespread and possibly irreversible in atolls and arctic coasts. The lower estimates for deltas are still a concern given these geographies' population sizes and economic importance globally."

The expert group developed a qualitative structured judgment -- the Global Adaptation Progress Tracker (GAP-Track) -- to assess adaptation efforts, progress and gaps, as part of the framework for the Global Goal on Adaptation established under the Paris Agreement in 2015.

Dr Magnan said: "Countries still struggle finding a way to operationalize the Global Goal on Adaptation and to conduct the Global Stocktake (GST) series that aims to collectively track adaptation progress and gaps, with a first iteration due at COP28 in the United Arab Emirates.

"The multi-dimensional and locally grounded assessment developed in this study for coastal adaptation confirms the need to drastically scale up adaptation policy and action around the globe, from local governments and stakeholders to the international climate policy arena.

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Study reveals our European ancestors ate seaweed and freshwater plants

For many people seaweed holds a reputation as a superfood, heralded for its health benefits and sustainability, but it appears our European ancestors were ahead of the game and were consuming the nutrient-rich plant for thousands of years.

Researchers say they have found "definitive" archaeological evidence that seaweeds and other local freshwater plants were eaten in the mesolithic, through the Neolithic transition to farming and into the Early Middle Ages, suggesting that these resources, now rarely eaten in Europe, only became marginal much more recently.

The study, published in Nature Communications, reveals that while aquatic resources were exploited, the archaeological evidence for seaweed is only rarely recorded and is almost always considered in terms of non-edible uses like fuel, food wrappings or fertilisers.

Historical accounts report laws related to collection of seaweed in Iceland, Brittany and Ireland dating to the 10th Century, while sea kale is mentioned by Pliny as a sailor's anti-scurvy remedy.

By the 18th Century seaweed was considered as famine food, and although seaweed and freshwater aquatic plants continue to be economically important in parts of Asia, both nutritionally and medicinally, there is little consumption in Europe.

The team, led by archaeologists from the universities of Glasgow and York, examined biomarkers extracted from dental calculus from 74 individuals from 28 archaeological sites across Europe, from north Scotland to southern Spain, which revealed "direct evidence for widespread consumption of seaweed and submerged aquatic and freshwater plants."

Samples where biomolecular evidence survived revealed consumption of red, green or brown seaweeds, or freshwater aquatic plants, with one sample from Orkney also containing evidence for a Brassica, most likely sea kale.

There are approximately 10,000 different species of seaweeds in the world, however only 145 species are eaten today, principally in Asia.

The researchers hope that their study will highlight the potential for including more seaweeds and other local freshwater plants in our diets today -- helping Europeans to become healthier and more sustainable.

Karen Hardy, Professor of Prehistoric Archaeology at the University of Glasgow and Principal Investigator of the Powerful Plants project, said: "Today, seaweed and freshwater aquatic plants are virtually absent from traditional, western diets and their marginalisation as they gradually changed from food to famine resources and animal fodder, probably occurred over a long period of time, as has also been detected elsewhere with some plants.

"Our study also highlights the potential for rediscovery of alternative, local, sustainable food resources that may contribute to addressing the negative health and environmental effects of over-dependence on a small number of mass-produced agricultural products that is a dominant feature of much of today's western diet, and indeed the global long-distance food supply more generally."

"It is very exciting to be able to show definitively that seaweeds and other local freshwater plants were eaten across a long period in our European past."

Co author on the paper, Dr Stephen Buckley, from the Department of Archaeology at the University of York, said "The biomolecular evidence in this study is over three thousand years earlier than historical evidence in the Far East.

"Not only does this new evidence show that seaweed was being consumed in Europe during the Mesolithic Period around 8,000 years ago when marine resources were known to have been exploited, but that it continued into the Neolithic when it is usually assumed that the introduction of farming led to the abandonment of marine dietary resources.

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NASA's Webb captures an ethereal view of NGC 346

Filaments of dust and gas festoon this star-forming region in a new infrared image from MIRI.

One of the greatest strengths of NASA's James Webb Space Telescope is its ability to give astronomers detailed views of areas where new stars are being born. The latest example, showcased here in a new image from Webb's Mid-Infrared Instrument (MIRI), is NGC 346 -- the brightest and largest star-forming region in the Small Magellanic Cloud.

The Small Magellanic Cloud (SMC) is a satellite galaxy of the Milky Way, visible to the unaided eye in the southern constellation Tucana. This small companion galaxy is more primeval than the Milky Way in that it possesses fewer heavy elements, which are forged in stars through nuclear fusion and supernova explosions, compared to our own galaxy.

Since cosmic dust is formed from heavy elements like silicon and oxygen, scientists expected the SMC to lack significant amounts of dust. However the new MIRI image, as well as a previous image of NGC 346 from Webb's Near-Infrared Camera released in January, show ample dust within this region.

In this representative-color image, blue tendrils trace emission from material that includes dusty silicates and sooty chemical molecules known as polycyclic aromatic hydrocarbons, or PAHs. More diffuse red emission shines from warm dust heated by the brightest and most massive stars in the heart of the region. An arc at the center left may be a reflection of light from the star near the arc's center. (Similar, fainter arcs appear associated with stars at lower left and upper right.) Lastly, bright patches and filaments mark areas with abundant numbers of protostars. The research team looked for the reddest stars, and found 1,001 pinpoint sources of light, most of them young stars still embedded in their dusty cocoons.

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'Starquakes' could explain mystery signals

Fast radio bursts, or FRBs, are an astronomical mystery, with their exact cause and origins still unconfirmed. These intense bursts of radio energy are invisible to the human eye, but show up brightly on radio telescopes. Previous studies have noted broad similarities between the energy distribution of repeat FRBs, and that of earthquakes and solar flares. However, new research at the University of Tokyo has looked at the time and energy of FRBs and found distinct differences between FRBs and solar flares, but several notable similarities between FRBs and earthquakes. This supports the theory that FRBs are caused by "starquakes" on the surface of neutron stars. This discovery could help us better understand earthquakes, the behavior of high-density matter and aspects of nuclear physics.

The vastness of space holds many mysteries. While some people dream of boldly going where no one has gone before, there is a lot we can learn from the comfort of Earth. Thanks to technological advances, we can explore the surface of Mars, marvel at Saturn's rings and pick up mysterious signals from deep space. Fast radio bursts are hugely powerful, bright bursts of energy which are visible on radio waves. First discovered in 2007, these bursts can travel billions of light years but typically last mere thousandths of a second. It has been estimated that as many as 10,000 FRBs may happen every day if we could observe the whole sky. While the sources of most bursts detected so far appear to emit a one-off event, there are about 50 FRB sources which emit bursts repeatedly.

The cause of FRBs is unknown, but some ideas have been put forward, including that they might even be alien in origin. However, the current prevailing theory is that at least some FRBs are emitted by neutron stars. These stars form when a supergiant star collapses, going from eight times the mass of our sun (on average) to a superdense core only 20-40 kilometers across. Magnetars are neutron stars with extremely strong magnetic fields, and these have been observed to emit FRBs.

"It was theoretically considered that the surface of a magnetar could be experiencing a starquake, an energy release similar to earthquakes on Earth," said Professor Tomonori Totani from the Department of Astronomy at the Graduate School of Science. "Recent observational advances have led to the detection of thousands more FRBs, so we took the opportunity to compare the now large statistical data sets available for FRBs with data from earthquakes and solar flares, to explore possible similarities."

So far, statistical analysis of FRBs has focused on the distribution of wait times between two successive bursts. However, Totani and co-author Yuya Tsuzuki, a graduate student in the same department, point out that calculating only the wait-time distribution does not take into account correlations that might exist across other bursts. So the team decided to calculate correlation across two-dimensional space, analyzing the time and emission energy of nearly 7,000 bursts from three different repeater FRB sources. They then applied the same method to examine the time-energy correlation of earthquakes (using data from Japan) and of solar flares (using records from the Hinode international mission to study the sun), and compared the results of all three phenomena.

Totani and Tsuzuki were surprised that, in contrast to other studies, their analysis showed a striking similarity between FRBs and earthquake data, but a distinct difference between FRBs and solar flares. Totani explained: "The results show notable similarities between FRBs and earthquakes in the following ways: First, the probability of an aftershock occurring for a single event is 10-50%; second, the aftershock occurrence rate decreases with time, as a power of time; third, the aftershock rate is always constant even if the FRB-earthquake activity (mean rate) changes significantly; and fourth, there is no correlation between the energies of the main shock and its aftershock."

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Research shows wildfire smoke may linger in homes long after initial blaze

Newly published research on indoor air quality from Colorado State University shows wildfire smoke may linger in homes long after the initial blaze has been put out or winds have shifted.

The findings, published in Science Advances, show that wildfire smoke can attach to home surfaces like carpet, drapes or counters -- extending the exposure for those inside and potentially causing health problems even after an initial cleaning activity by air purifiers. However, Professor Delphine Farmer said the research also shows that simple surface cleaning -- like vacuuming, dusting or mopping -- can reduce exposure and limit risk.

The research illustrates the hidden and persistent health threats many in the Western U.S. are facing given the increase in wildfires over the last decade, she said.

"This research shows that events like the Marshall Fire in Colorado, the wildfires in Canada and the recent fires in Hawaii present serious exposure potential -- not just when they occur but well after," said Farmer, who is based in the Department of Chemistry at CSU. "This paper is a key initial step towards providing actionable and practical information on how to protect yourself and clean your home."

To better understand how smoke enters and then stays in buildings, researchers burned pine wood chips in a net zero energy residential testing facility operated by the National Institute of Standards and Technology (NIST) in Maryland. That facility is frequently used to study how different systems impact the ways energy, water and air move through a single-family house. The detailed instrumentation available for that work was perfectly suited to this research, said Dustin Poppendieck, an environmental researcher at NIST who helped coordinate the project.

"The NIST Net Zero House allowed the researchers to track the movement and transformation of chemicals in the air and onto surfaces in real time using instruments in ways that don't interfere with the behavior of the smoke," said Poppendieck.

Those smoke injection sessions occurred regularly over several days, and Farmer said the total amount applied was comparable or slightly under the particulate levels seen during the Canadian wildfires. The team then took careful measurements of air quality levels and surface conditions after opening exterior doors and windows, cleaning and use of the home's built-in air cleaning systems.

The CSU team was particularly interested in the gas-phase of compounds developing from the smoke, while other teams from the University of California San Diego, CU Boulder and the University of North Carolina Chapple Hill explored different phases and interactions across the home. The team then compared findings between states to confirm what was actually happening in the home after the burn.

Farmer said findings from this interdisciplinary research approach could also be applicable to other large air pollution events like the train derailment in East Palestine, Ohio, where the same principles of compounds sticking to surfaces are likely to occur.

Because there has not been a lot of similar indoor air research, the team leaned on previous findings from others around the effects of cigarette smoke to inform their approach. Farmer said burning nicotine causes specific compounds with well-known health concerns and that the comparison to their project findings was informative.

"Nicotine reacts on surfaces to create a particularly nasty set of compounds called nitrosamines, which is where the real concern from thirdhand smoke that is left behind comes from," she said. "Whereas with wildfire smoke, we found there was a huge diversity of organic compounds that stick to surfaces, which then slowly bleed off."

The amount, persistence and variety of compounds from the wildfire smoke in each case could potentially change the recommended approaches for cleaning the indoor spaces. Farmer said that is an area of research the team hopes to explore in the future. For now, she said the team was able to show that the amount of smoke left on surfaces was proportional to the surface area that was cleaned. That means simple cleaning and specifically addressing large but little noticed spaces that may trap harmful compounds such as cabinets and HVAC systems could be beneficial right away.

"As we continue this research, we would like to know just how effective different cleaning approaches are and when residents should move from relatively simple steps like using commercial cleaning supplies for mopping to more drastic steps like replacing the drywall altogether," Farmer said.

Farmer's team was also recently funded by the W.M. Keck Foundation to research how smog may enter and remain in the home in much the same way as wildfire smoke. That work will be particularly important in Colorado where ground-level ozone pollution is a continuing issue.

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