Category: 7. Science

NASA has called it quits on attempts to contact its Lunar Trailblazer probe, notching up a failure in its low-cost, high-risk science program.

The probe, designed to map lunar water, launched on February 26, hitching a ride with the second Intuitive Machines robotic lunar lander. All went well at first. The spacecraft separated from the rocket approximately 48 minutes after launch and established communications.

However, by the next day, contact was lost. It appeared the solar arrays were not properly oriented toward the Sun, and the probe’s batteries had been depleted. The spacecraft was tracked from Earth, and observations indicated it was in a slow spin as it drifted off into deep space.

Andrew Klesh, Lunar Trailblazer’s project systems engineer at NASA’s Jet Propulsion Laboratory in Southern California, said: “As Lunar Trailblazer drifted far beyond the Moon, our models showed that the solar panels might receive more sunlight, perhaps charging the spacecraft’s batteries to a point it could turn on its radio.”

NASA gave the stricken probe a few extra weeks in July to respond, but as the month drew to a close, so too did NASA’s efforts to recover the spacecraft. Even if there had been sufficient power to turn on the radio, the signal would have been too weak for controllers to receive telemetry and issue commands.

The mission aimed to produce high-resolution maps of water on the Moon’s surface and determine what form the water is in, how much is there, and how it changes over time. The data would have proved useful in future robotic and human missions to the lunar surface.

The Lunar Trailblazer was selected by NASA’s SIMPLEx (Small Innovative Missions for Planetary Exploration) competition. SIMPLEx is about lowering costs by adopting a higher risk posture and less stringent requirements for oversight and management.

Readers would be forgiven for a sense of déjà vu. At the end of the last century, NASA adopted a “faster, better, cheaper” approach to missions as it faced substantial budget cuts. The strategy, which was to increase mission cadence and lower costs by accepting greater risks, resulted in some successes, notably the Mars Sojourner rover – but also losses, such as the Mars Polar Lander.

As NASA faces further budget cuts, robotic missions with lower costs and a greater acceptance of risk are set to become more commonplace. ®

New research on the fossilised teeth of an ancient predator reveals how a 56-million-year-old mammal adapted its diet to survive extreme global warming, offering lessons on surviving climate change for wildlife today

The future of conservation and animal research

New research from Rutgers University has uncovered how an ancient, jackal-sized predator adapted its diet to survive a period of extreme global warming 56 million years ago. This discovery, based on the study of fossilised teeth from the extinct mammal Dissacus praenuntius, provides insights into how today’s wildlife might cope with modern climate change and what it means for the future of conservation.

Published in the journal Palaeogeography, Palaeoclimatology, Palaeoecology, the findings highlight the critical role of dietary flexibility in surviving environmental upheaval. According to Andrew Schwartz, a doctoral student who led the research, the ancient omnivore responded to the Paleocene–Eocene Thermal Maximum (PETM)—a period of rapid global warming—by shifting its diet from tough flesh to harder materials like bones. This adaptation not only ensured its survival but also offers a powerful lesson for contemporary conservation efforts.

Examining an ancient ecosystem: Surviving climate change

The researchers, using a technique called dental microwear texture analysis, examined the microscopic pits and scratches on the fossilised teeth of Dissacus praenuntius. These tiny marks reveal what the animal was chewing in the weeks leading up to its death.

The ancient predator, described by Schwartz as a “super weird mammal” with an oversized head and tiny hooves, was about the size of a jackal or coyote. Before the PETM, its dental wear patterns were similar to those of modern cheetahs, indicating a diet of primarily tough flesh. However, during and after this period of global warming, the teeth showed signs of crunching harder, more brittle foods like bone, similar to the wear seen on the teeth of modern lions and hyenas.

This dramatic dietary shift, the researchers concluded, was likely a response to food scarcity as its usual prey became smaller or less available due to the changing climate.

Being a “Generalist”

The study also shed light on the broader ecological consequences of rapid warming. The dietary shift was accompanied by a modest reduction in the predator’s body size, a change that earlier hypotheses had attributed solely to hotter temperatures.

However, this new research suggests that limited food availability played a more significant role. The findings underscore the importance of adaptability, or being a “generalist” in ecological terms. Schwartz explains that while specialising in a specific food source may be beneficial in the short term, it’s a risky strategy when the environment changes.

Generalists, like jackals or raccoons, which can eat a variety of foods, are equipped to survive climate change.

This insight is particularly relevant for modern conservation biology, as it can help scientists identify which species are most vulnerable to habitat loss and climate stress. Animals with narrow diets, such as pandas, face a greater risk of extinction, while more adaptable species may fare better.

Lessons from the past for the future

The PETM lasted about 200,000 years, but the changes it triggered were both fast and dramatic. Schwartz emphasises that by studying such ancient events, we can better understand and predict the consequences of today’s climate crisis. “One of the best ways to know what’s going to happen in the future is to look back at the past,” he said. The study’s conclusion that rapid warming can disrupt food webs and force animals to adapt or face extinction serves as a powerful warning for our own time.

Although Dissacus was a successful and adaptable species that thrived for 15 million years, it eventually went extinct, likely due to a combination of environmental changes and competition from other animals. This serves as a reminder that even the most resilient species have their limits.

By understanding the choices and challenges faced by ancient predators like Dissacus, researchers hope to provide valuable, actionable information for modern conservationists and policymakers working to protect our planet’s biodiversity in the face of an uncertain future.

The study, published online in Cell on August 4, achieves multiple types of precise DNA manipulations ranging from kilobase to megabase scale in higher organisms, especially plants.

Extensive research has demonstrated the immense potential of the site-specific recombinase Cre-Lox system for precise chromosomal manipulation. However, its broader application has been hindered by three critical limitations:

1. Reversible recombination reactions — stemming from the inherent symmetry of Lox sites — can negate desired edits.
2. The tetrameric nature of Cre recombinase complicates engineering efforts, hindering activity optimization.
3. Residual Lox sites after recombination may compromise editing precision.

The research team addressed each of these challenges and developed novel methods to advance the state of this technology. First, they built a high-throughput platform for rapid recombination site modification and proposed an asymmetric Lox site design. This led to the development of novel Lox variants that reduce reversible recombination activity by over 10-fold (approaching the background level of negative controls) while retaining high-efficiency forward recombination.

They then leveraged their recently developed AiCE (AI-informed Constraints for protein Engineering), model — a protein-directed evolution system integrating general inverse folding models with structural and evolutionary constraints — to develop AiCErec, a recombinase engineering method. This approach enabled precise optimization of Cre’s multimerization interface, yielding an engineered variant with a recombination efficiency 3.5 times that of wild-type Cre.

Lastly, they designed and refined a scarless editing strategy for recombinases. By harnessing the high editing efficiency of prime editors, they developed Re-pegRNA, a method that uses specifically designed pegRNAs to perform re-prime editing on residual Lox sites, precisely replacing them with the original genomic sequence, thereby ensuring seamless genome modifications.

The integration of these three innovations led to the creation of two programmable platforms, PCE and RePCE. These platforms allow flexible programming of insertion positions and orientations for different Lox sites, enabling precise, scarless manipulation of DNA fragments ranging from kilobase to megabase scale in both plant and animal cells. Key achievements include: targeted integration of large DNA fragments up to 18.8 kb, complete replacement of 5-kb DNA sequences, chromosomal inversions spanning 12 Mb, chromosomal deletions of 4 Mb, and whole-chromosome translocations.

As a proof of concept, the researchers used this technology to create herbicide-resistant rice germplasm with a 315-kb precise inversion, showcasing its transformative potential for genetic engineering and crop improvement.

This pioneering work not only overcomes the historical limitations of the Cre-Lox system but also opens new avenues for precise genome engineering in a variety of organisms.

In the story of conservation, certain characters steal the spotlight. We celebrate the survival of endangered animals, restore their habitats, and marvel at their recovery.

But hidden beneath these victories is a quieter, almost invisible loss – one that rarely earns public attention or sympathy. This is the story of the kākāpō and the silent extinction of the parasites that once lived alongside it.

Vanishing kākāpō parasites

Researchers from the University of Adelaide, Manaaki Whenua-Landcare Research, and the University of Auckland have uncovered a surprising shift in the lives of New Zealand’s kākāpō parrots. Over 80 percent of the parasites found in their droppings before the 1990s have disappeared.

Using ancient DNA and microscopic analysis, the team studied feces dating back more than 1,500 years.

The researchers discovered that nine of the 16 parasite types vanished before the 1990s, the same period when the birds began full-population management. Another four species disappeared after this conservation work began.

Parasites disappear with their hosts

“Despite their sometimes negative portrayal, parasites are increasingly appreciated for their ecological importance,” said the University of Adelaide‘s Dr. Jamie Wood. These organisms are among the most successful and widespread lifeforms on Earth.

Parasites are not always harmful invaders. Many play subtle yet vital roles in ecosystems. They help train host immune systems, regulate disease, and sometimes outcompete more dangerous parasites.

Almost every free-living animal harbors parasites, making them one of the most widespread life forms. Yet this close connection creates a risk.

Parasites depend heavily on specific host species to survive and reproduce. If the host population declines – due to disease, habitat loss, or conservation interference – the parasites may also disappear.

These losses often go unnoticed, yet they could have lasting effects on host health and ecological balance. When parasites vanish, we may lose not just pests, but essential contributors to the natural world.

Parasites may vanish before their hosts

This study focuses on the concept of co-extinction, a process where one species disappears because it depends entirely on another species that is going extinct.

In this case, the dependent species is a parasite, and the host is the species it lives on. If the host population declines or dies out, the parasite often can’t survive. But the key point here is that parasites may vanish even before the host does.

“Predictive models indicate that parasites may go extinct before their hosts during the coextinction process as opportunities to transmit between host individuals diminish,” said Dr. Wood.

Even if the host species is saved later through conservation efforts, its lost parasites might never come back. This has unknown consequences.

Parasites are hard to study, because they’re rarely recorded before they disappear. By the time scientists realize they’re gone, it’s too late to learn about what role they played.

Wider implications for biodiversity

The study highlights that parasite extinctions might happen more often than previously thought.

“Our new research indicates that parasite extinctions may be far more prevalent than previous estimates suggest, with unknown impacts on their hosts and their ecosystems,” noted Dr. Wood.

Study lead author Alexander Boast from Manaaki Whenua–Landcare Research was taken aback by the findings.

“The level of parasite loss in kākāpō was greater than we had expected, and very few parasite species were found in both ancient and modern kākāpō populations,” said Boast.

“Thus, it seems that endangered species everywhere may possess fractions of their original parasite communities.”

Protecting kākāpō parasites from extinction

As biodiversity declines, the loss of less visible species like parasites may also increase.

“Global rates of climate change, ecosystem modification, and biodiversity decline continue to rise, which means there is an increasingly urgent need to recognize and understand the downstream impacts on dependent species, such as parasites, mutualists, or predators,” said Dr. Wood.

“Documenting parasite extinction, how quickly it can unfold, and estimating the number of presently threatened parasites are key first steps toward a ‘global parasite conservation plan’ and supporting informed predictions for past, present, and future parasite losses.”

The study is published in the journal Current Biology.

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We usually think of satellites as small objects orbiting planets or stars. But in the broader universe, galaxies themselves can have satellites—smaller galaxies bound by gravity that orbit a larger host, carrying with them stars, gas, dust, and dark matter.

Most of what we know about satellite galaxies comes from studying the Milky Way and other similarly large galaxies. But a new study led by Dartmouth astronomers broadens that understanding by exploring the satellites of dwarf galaxies—systems less than a tenth the size of the Milky Way.

The multi-institutional survey triples the number of dwarf galaxies surveyed for satellites, the researchers report in The Astrophysical Journal . The study identifies 355 candidate satellite galaxies, including 264 that were previously undocumented. The researchers suggest that 134 of these candidates are highly likely to be satellite galaxies.

“Studying these systems can help us piece together conditions in the early universe,” says author Burçin Mutlu-Pakdil , an assistant professor of physics and astronomy at Dartmouth.

“This project fills a critical gap, offering fresh insights into the process of how galaxies form and its connection to dark matter,” Mutlu-Pakdil says. “Our goal is to build a statistical sample of the smallest galaxies in the universe, as they are the most dominated by dark matter and serve as clean laboratories for understanding its nature.”

By analyzing the satellite galaxies orbiting host galaxies of various sizes and environments, the researchers aim to uncover how external conditions influence satellite formation. For instance, studies of large, Milky Way-sized galaxies suggest that larger galaxies tend to host a greater number of satellite galaxies.

“With this survey, we’ll be able to test whether those predictions hold true with much smaller host galaxies,” says Laura Hunter, a postdoctoral fellow in Mutlu-Pakdil’s research group and corresponding author of the study.

“Astronomy is a field where you can’t run experiments,” Hunter says. “All you can do is observe and make as many measurements as you can, and then put that data into a simulation and see whether it reproduces your observations. If it doesn’t, that tells us that there’s something wrong with our assumptions or our model of the universe.”

To search for dwarf satellites, the team analyzed publicly available imaging data from the Dark Energy Spectroscopic Instrument (DESI) Legacy Imaging Surveys. In addition to Hunter and Mutlu-Pakdil, co-authors of the study include Dartmouth graduate student Emmanuel Durodola and Rowan Goebel-Bain ’25.

The researchers selected 36 host galaxies to investigate. The hosts varied in size and in proximity to other galaxies, both of which are factors that could impact satellite formation. The team used an algorithm to remove “noise” from the images, such as bright sources of light from other stars or galaxies, and to identify objects that could be satellite galaxies. They then visually inspected each candidate satellite to rule out those that were due to image defects or faint light halos around bright stars or galaxies.

This survey is the first step towards understanding how dwarf satellites differ from the satellite galaxies of larger hosts. The team is currently conducting a follow-up campaign to confirm that the candidate satellites are indeed satellite galaxies, and to characterize properties such as their size, distribution, how much gas and debris they contain, and their rates of star formation.

“Getting the answers will require a lot of resources and telescope time, but the impact will be incredible for understanding the nature of dark matter and galaxy formation at the smallest scale,” Mutlu-Pakdil says. “Each one of them holds a little clue about the physics of how galaxies form.”

As giant planet HIP 67522 b orbits its host star, it triggers its own doom. The planet orbits HIP 67522, a young star slightly larger than the Sun, in just 7 Earth days. At just 17 million years old, the star is far more active than our Sun, regularly flaring and releasing massive amounts of energy and stellar material.

By using observations from three exoplanet telescopes, scientists have found that these flares don’t occur at random times and locations like on our Sun. Instead, they are concentrated at a particular time in the planet’s orbit, which suggests that the planet itself could be triggering the flares. What’s more, the flares are also pointed at the planet, bombarding it with nearly 6 times more radiation than it would experience if the flares occurred at random.

“We want to understand the space weather of these systems in order to understand how planets evolve over time, how much high-energy radiation they get, how much wind they’re exposed to, what consequences that has on the evolution of their atmospheres, and, down the line, habitability,” said Ekaterina Ilin, lead researcher on the discovery and an astronomer at the Netherlands Institute for Radio Astronomy (ASTRON) in Dwingeloo.

Magnetic Interactions

Space weather is common in our solar system. At Earth’s relatively safe distance from the Sun, space weather manifests as aurorae and enhanced solar wind that, nonetheless, can wreak havoc on navigation and communication systems.

But in exoplanet systems, space weather can be far more deadly. Stars have strong magnetic fields, which are even stronger and more turbulent when stars are young. A star’s magnetic field lines stretch out from its surface, carrying superheated plasma along with them. Field lines regularly twist and tangle and coil until they eventually snap back into place, releasing stored energy and stellar material in a flare or coronal mass ejection (CME).

Astronomers have observed exoplanets orbiting so close to their stars that their atmospheres or even rocky surfaces are being blasted away by intense stellar radiation, winds, and flares. But for decades, astronomers have theorized that the connection between stars and close-in planets can go both ways.

According to the theory, some planets orbit so close to their star that they are inside the star’s magnetic boundary, the so-called sub-Alfvénic zone. Such a so-called short-period planet could gather up magnetic energy like a windup toy as it orbits and release it in waves along the star’s magnetic field lines. When the energetic waves reach the star’s surface, they could trigger a flare back toward the planet.

The idea was born after the discovery of the first exoplanet—51 Pegasi b—in 1995 showed astronomers that planets could orbit extremely close to their host stars (51 Pegasi b has a 4.23-day orbit). Ilin said that although the theory has existed since the early 2000s, it has taken a while to find even one exoplanet that might fit the bill because most planets discovered thus far orbit much older stars with few flares and weak magnetic fields.

Too Close for Comfort

Ilin and her colleagues combed through thousands of confirmed and candidate exoplanets detected by the now-retired Kepler Space Telescope and the extant Transiting Exoplanet Survey Satellite (TESS). They looked for young, flaring stars with close-in giant planets—a very broad search with hundreds of results—and narrowed their search down by looking for planets that might orbit within the sub-Alfvénic zone and for stars with strange flare timings.

“It was really a shot in the dark,” Ilin said.

After a long, tedious search, the team homed in on HIP 67522 and its two planets: planet HIP 67522 b, with its 7-day orbit, and a second giant planet with a 14-day orbit. The star’s flares were clustered together, but only barely within the margin of significance.

“The expectation was that it would have one of the strongest magnetic interactions based on how close the star is to the [inner] planet, how big the star is, how big the planet is, how young it is, [and] how strong a magnetic field we expect,” Ilin said. Despite the marginal significance, she thought, “Oh, actually, it might be worth a second look.”

The researchers observed the star with the European Space Agency’s Characterising Exoplanets Satellite (CHEOPS) for 5 years. They characterized 15 stellar flares during that period, a typical number for this size and age of star, but found that the flares clustered together when the innermost planet passed between the star and the telescope’s vantage point at Earth.

“When the planet is close to transit, the flaring goes up by a factor of 5 or 6, and that should not happen,” Ilin explained. “Statistically, almost impossible.”

“It is fascinating to see clustered flaring following the planet as it orbits its star,” said Evgenya Shkolnik, an astrophysicist at Arizona State University in Tempe who was not involved with this research. Some of Shkolnik’s past work investigated enhanced stellar activity in Sun-like stars with hot Jupiters, but those stars were much older and did not flare as much as HIP 67522. “It makes sense that more flares could be triggered through the same type of magnetic star-planet interactions we observed,” she said.

Like other short-period giant planets, HIP 67522 b likely would have been losing its atmosphere to stellar radiation no matter what because of how closely its orbits—indeed, the planet is about the size of Jupiter but just 5% its mass. But because the flares are synced with HIP 67522 b’s orbital period, Ilin’s team calculated that HIP 67522 b is experiencing roughly 6 times the stellar radiation that it would if the flares were randomly distributed, and the corresponding CMEs are pointed directly at it.

The team’s simple estimates show that because of this increased radiation, the planet is losing its atmosphere about twice as fast as it would otherwise.

“It makes its life even worse by whipping up this interaction…and firing all these CMEs directly into the planet’s face,” Ilin said. These results were published in Nature.

“This discovery is extremely exciting,” said Antoine Strugarek, an astrophysicist at the French Alternative Energies and Atomic Energy Commission in Paris who was not involved with the research. “Such magnetic interactions are clearly the prime candidate to explain the observed phenomenon, and no other theories are really convincing to explain these observations, to the best of my knowledge.”

Expanding the Search

Strugarek explained that the magnetic interaction observed in the HIP 76522 system has a few analogs in our own solar system. The Sun experiences “sympathetic flares,” he said, in which a solar flare in one spot can trigger another one nearby—they account for about 5% of solar flares. And in the Jupiter system, the Galilean moons Io, Ganymede, and Europa propagate waves along their orbits that trigger polar aurorae on Jupiter.

For HIP 76522, “the theory is that the perturbation originates from the exoplanet. This is definitively a possibility, and extremely exciting for future research,” Strugarek said. He added that he would like to see future work constrain the geometry of HIP 76522’s magnetic field to better understand the star-planet connection.

He also wants to go back into the archives to look for more exoplanets like this. “Now that we have one tentative system, we need to scrutinize all the compact star-planet systems with large flares for such occurrences,” Strugarek said. “This should be ubiquitous for very compact systems.

Shkolnik added, “I would love to see dedicated observing programs at both higher- and lower-energy wavelengths, namely, in the far-ultraviolet, submillimeter, and radio wavelengths.” The far ultraviolet is more sensitive to flares, and finding more flares might confirm the theory that the planet is triggering them.

Thus far, HIP 76522 b is the only planet discovered to be magnetically influencing its star. Ilin said that when her team started looking into HIP 76522 b, it was the youngest short-period planet in their catalogs. TESS has since observed several more, and Ilin’s team is ready to investigate them.

The researchers also hope to flip the script on star-planet interactions. Instead of starting with an exoplanet and looking for clustered stellar flares, they want to first look for flare patterns and then find the planet causing them. The untested technique could detect exoplanets around stars that other detection methods struggle with: young, active stars.

“It is a bit of a statistically tough cookie,” she said, “but it will be quite exciting if we can make that happen.”

—Kimberly M. S. Cartier (@astrokimcartier.bsky.social), Staff Writer

Citation: Cartier, K. M. S. (2025), Exoplanet triggers stellar flares and hastens its demise, Eos, 106, https://doi.org/10.1029/2025EO250284. Published on 5 August 2025.

Text © 2025. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

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Marybeth Collins

Between 2003 and 2021, Earth saw a net gain in photosynthesis primarily driven by land plants, while marine phytoplankton productivity declined, according to a new study published August 1 in Nature Climate Change. The findings suggest that terrestrial ecosystems are becoming increasingly critical to global carbon uptake—but this shift may mask deeper vulnerabilities in the planet’s climate system.

Net primary production (NPP)—the amount of carbon plants and algae store after respiration—is a key indicator of ecosystem health and carbon cycle stability. Duke University researchers analyzed 19 years of satellite-based data across land and ocean, revealing an annual global increase of 0.1 billion metric tons of captured carbon, largely due to high-latitude forest growth and longer growing seasons.

“Net primary production determines ecosystem health, provides food and fibers for humans, mitigates anthropogenic carbon emissions, and helps to stabilize Earth’s climate,” said Yulong Zhang, lead author and research scientist at Duke’s Nicholas School of the Environment.

Rising Land Gains, Sinking Marine Losses

The study shows:

• Terrestrial NPP increased by 0.2 billion metric tons of carbon per year, especially in boreal and temperate zones like Canada, Siberia, and parts of Europe.
• Marine NPP declined by 0.1 billion metric tons of carbon per year, most notably in tropical Pacific and Indian Ocean regions, due to reduced nutrient mixing from ocean stratification.

These trends were tracked using multiple satellite datasets that measured chlorophyll activity, surface greenness, sea surface temperatures, and precipitation variability.

El Niño’s Outsized Influence

While land productivity has generally trended upward, ocean productivity proved more volatile. The decline in marine photosynthesis has been closely tied to El Niño and La Niña events, which shift trade winds and water column mixing patterns. These shifts are increasingly frequent and severe under global warming.

“The ocean’s primary production responds much more strongly to El Niño and La Niña than land ecosystems,” said Shineng Hu, co-author and assistant professor at Duke. “A series of La Niña events helped reverse marine declines briefly after 2015, but the long-term trend remains downward.”

Why It Matters

According to the Global Carbon Project and IPCC AR6 reports, oceans currently absorb about 25% of anthropogenic CO₂ emissions. A continued decline in marine primary productivity would weaken this vital sink, increase atmospheric CO₂ concentrations, and destabilize tropical food chains.

At the same time, while expanding forests help offset emissions, their future is also uncertain. Deforestation, wildfires, pest outbreaks, and drought-induced diebacks threaten the durability of terrestrial carbon sinks. In 2023 alone, the Amazon rainforest lost nearly 5,000 km² of canopy—its highest rate in five years.

Moreover, a 2024 study in Science Advances warned that boreal forest gains might slow as Arctic warming accelerates permafrost thaw and soil carbon loss.

Integrated Monitoring Urged

Zhang and his co-authors stress that monitoring Earth’s productivity requires a joined-up approach, covering both land and ocean ecosystems.

“Whether the decline in ocean primary production will continue—and how long and to what extent increases on land can make up for those losses—remains a key unanswered question,” Zhang said.

Looking Ahead

This new Earth system imbalance—forest productivity up, ocean productivity down—should influence how nations model carbon budgets and design climate policies. It reinforces the need for:

• Strong forest preservation and reforestation
• Reductions in nutrient runoff that further degrade ocean ecosystems
• Improved long-term satellite monitoring (like NASA’s upcoming PACE mission)

The ICL imaged by Englert and his colleagues revealed a special type of galactic merger happening in Abell 3667. Normally, Englert says, mergers that involve the largest galaxy in a cluster, called the brightest cluster galaxy or BCG, occur gradually as it steals stars from many smaller galaxies that surround it. But this new research shows something different happening in this case. Abell 3667 is actually made of two galaxy clusters, each with its own BCG, that are now merging together. The ICL bridge discovered by the researchers suggests that the larger BCG is stealing stars from the smaller one — an event known as a rapid or aggressive merger. As the two BCGs merge, so too do the smaller galaxies that surround them, making Abell 3667 the product of two merging clusters. Data from X-ray and radio frequency observations had suggested a rapid merger in Abell 3667, but this is the first optical evidence to back it up. 

The appearance of intracluster light in these new images offers a tantalizing preview of what’s to come when the Vera C. Rubin Observatory becomes fully operational later this year or early next. Using a telescope twice the size of Blanco and the largest camera ever built, the Rubin telescope will perform a 10-year scan deep into the entire southern sky, a project called the Legacy Survey of Space and Time.

“Rubin is going to be able to image ICL in much the same way as we did here, but it’s going to do it for every single local galaxy cluster in the southern sky,” Englert said. “What we did is just a small sliver of what Rubin is going to be able to do. It’s really going to blow the study of the ICL wide open.”

That will be a scientific bonanza for astronomers and astrophysicists. In addition to revealing the history of galaxy clusters, the ICL holds clues to some of the most fundamental mysteries of the universe, particularly dark matter — the mysterious, invisible stuff thought to account for most of the universe’s mass.

“ICL is quite important for cosmology,” Dell’Antonio said. “The distribution of this light should mirror the distribution of dark matter, so it provides an indirect way to ‘see’ the dark matter.”

Seeing the unseeable — that’s a powerful telescope. 

The Victor M. Blanco Telescope and the Vera C. Rubin Observatory are operated by NOIRLab, the U.S. national center for ground-based, nighttime optical astronomy operated by the National Science Foundation. The research was funded by NSF (AST-2108287), the U.S. Department of Energy (DE-SC-0010010) and the NASA Rhode Island Space Grant Consortium.

Japanese researchers say they have discovered the mechanism by which exposure to PM2.5 air pollution causes airway dysfunction, and how the resulting damage might be reversed.

A large portion of natural and human-made air pollutants fall under the PM2.5 category, which relates to airborne particles below 2.5µm diameter. It includes dust, vehicle exhaust and wildfire smoke. When inhaled, it is believed to cause severe airway damage and respiratory diseases. To understand how exactly air pollution particles affect the respiratory system, the researchers ran a series of experiments on mice. They exposed the mice to environmental pollutants and then examined their respiratory tracts for changes in structure and function.

“Our results were quite informative. We found that PM2.5 air pollutants negatively affect mucociliary clearance, a major protective mechanism in the respiratory tract,” said lead author, Noriko Shinjyo of the University of Osaka, which led the research. “Mucociliary clearance basically involves trapping pollutants in a sticky mucus and then sweeping the pollutants out the airway with hair-like projections called cilia.”

The researchers’ findings seemed to confirm that the pollutants caused oxidative injury in the airways, which facilitates the formation of lipid peroxide-derived aldehydes. This substance is a reactive aldehyde that damages the protective cells in the airway, including airway cilia. As damaged airway cells and cilia can no longer move debris and pollutants out of the airways, the risk of infection is increased.

The team also attempted to ascertain how to restore normal cellular function and reverse damage. For this, the researchers investigated how one gene from the ALDH family, known to protect the body against harmful aldehydes, may counter the effect of airway pollutants.

“Aldehyde dehydrogenase (ALDH1A1) is an enzyme that plays an important role in protection against aldehydes. We used experimental mice that lacked ALDH1A1 to investigate the impact of air pollutants without the gene,” said Yasutaka Okabe, senior author. “As expected, the mice had impaired cilia formation and function and high levels of aldehydes.”

The research team also appeared to find that the absence of ALDH1A1 left the cells at a higher risk of serious respiratory infection when exposed to air pollutants. The importance of ALDH1A1 was further emphasized when it was also found that drug-enhanced ALDH1A1 levels improved the mice’s mucociliary function in response to pollutants.

These findings appear to reveal how PM2.5 pollutants disrupt the lungs’ self-cleaning system. The work also offers a potential therapeutic target: the enzyme ALDH1A1.

The results were published in The Journal of Clinical Investigation.

A vast blob of hot rock moving slowly beneath the Appalachian Mountains in the northeastern US is now thought to be the result of a divorce between Greenland and Canada some 80 million years ago.

A study by an international team of researchers challenges the existing consensus in both geographical and chronological terms. It was previously thought the breaking up of the North American and African continents was responsible, some 180 million years ago.

To test their assertion, the researchers used a combination of existing data and computer modeling to link the hot blob to a geological formation in the Labrador Sea in the North Atlantic dated to around 85-80 million years ago.

Related: Mysterious Blobs Deep Inside Earth May Fuel Deadly Volcanic Eruptions

“This thermal upwelling has long been a puzzling feature of North American geology,” says earth scientist Thomas Gernon, from the University of Southampton in the UK.

“It lies beneath part of the continent that’s been tectonically quiet for 180 million years, so the idea it was just a leftover from when the landmass broke apart never quite stacked up.”

Technically known as the Northern Appalachian Anomaly (NAA), the 350-kilometer- (217-mile-) wide blob of hot rock hasn’t been in any particular hurry to get to its present location, moving at a rate of around 20 kilometers every million years. At that rate, the blob should pass New York in around 10 to 15 million years or so.

However, the research team suggests this anomaly is one of the main reasons the Appalachians are still in place. The heat helps the continental crust remain buoyant, contributing to the mountains being uplifted further over the years.

The new study builds on previous work from some of the same researchers. Known as the ‘mantle wave’ theory, it posits blobs of hot rock rise in a lava-lamp style when continents break apart, triggering a variety of geological phenomena such as volcanic eruptions and formation of mountains.

“Our earlier research shows that these drips of rock can form in series, like domino stones when they fall one after the other, and sequentially migrate over time,” says geophysicist Sascha Brune, from the GFZ Helmholtz Centre for Geosciences in Germany.

“The feature we see beneath New England is very likely one of these drips, which originated far from where it now sits.”

Further analysis and tracking of the hot rock will help to confirm its origins. Meanwhile, the same theories and techniques can be used to identify other geological features like this.

In fact, the researchers think they might have already spotted a ‘mirror’ to the NAA, under north-central Greenland and also originating from the Labrador Sea.

“The idea that rifting of continents can cause drips and cells of circulating hot rock at depth that spread thousands of kilometers inland makes us rethink what we know about the edges of continents both today and in Earth’s deep past,” says Derek Keir, a geophysicist from the University of Southampton.

The research has been published in Geology.