Schematic of the layered systems: CO2 deposited on (a) bare gold (Au), (b) water ice on gold, (c) a silicate film on gold, and (d) ice on a silicate film on top of gold. In panel (b), the ice layers consist of different thicknesses of pASW, while in panel (d), the ice layers are either apolar (CO, CH4) or polar (pASW, CW, CH3OH, or CH3OH:H2O in a 1:1 ratio). — astro-ph.GA
Carbon dioxide is one of the three most abundant species within the ice mantles around dust grains inside molecular clouds.
Since a substantial amount of interstellar grains is made of siliceous materials, we have studied the infrared profile of CO2 deposited on top of a bare and ice-coated amorphous silicate (MgFeSiO4) film using reflection absorption infrared spectroscopy (RAIRS).
In contrast to a metal surface, the CO2 IR profile shows a relaxation of the metal surface selection rule in the presence of the bare MgFeSiO4 dust grain analog, which brings the IR profile closer to the observational spectra while maintaining the sensitivity of RAIRS. Experiments with the underlying CO and CH4 ices show that their presence facilitates structural changes toward crystalline ice for the deposited CO2 at much lower temperatures than on the polar ice layers.
Warming-up experiments of CO2 showed that it tends to stay on the silicate surface for much longer than on the gold surface without the silicate layer. We noticed for the first time a split in the 13CO2 IR feature on the pure or ice-covered silicate grain as a marker for the onset of diffusion.
The laboratory 13CO2 profile then closely resembles recent JWST observations of this feature around young and embedded protostars, suggesting that it can be linked to the observed feature.
Tushar Suhasaria, Vanessa Leuschner, Cornelia Jaeger, Caroline Gieser, Thomas Henning
Comments: 13 pages, 6 figures, 2 tables Subjects: Astrophysics of Galaxies (astro-ph.GA) Cite as: arXiv:2507.00836 [astro-ph.GA] (or arXiv:2507.00836v1 [astro-ph.GA] for this version) https://doi.org/10.48550/arXiv.2507.00836 Focus to learn more Submission history From: Tushar Suhasaria Dr [v1] Tue, 1 Jul 2025 15:08:11 UTC (363 KB) https://arxiv.org/abs/2507.00836 Astrobiology,
Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻
The 134Xe/132Xe versus 136Xe/132Xe diagram showing the composition of Tatahouine (#13349) and Shalka (#6766 C) measured at different heating steps, including those of Michel & Eugster (1994) and Eugster & Michel (1995) for comparison. The 238U and 244Pu fission Xe data are from Porcelli et al. (2002). Q-Xe (Q phase is the main carrier of heavy noble gases in chondrites) is from Busemann et al. (2000), SW-Xe (SW stands for solar wind) is from Meshik et al. (2020), U-Xe is from Pepin & Porcelli (2002) and Air (corresponding to Earth’s atmosphere) — astro-ph.EP
A bombardment of comets is thought to have occurred in the inner solar system as a result of a dynamical instability among the giant planets after gas disk dispersal.
Vesta, the second largest asteroid in the main asteroid belt, likely differentiated before gas disk dispersal, implying its crust witnessed the cometary bombardment. The composition of HED meteorites, which represent fragments of Vesta’s crust, could therefore have been altered by cometary impacts.
Here we combine noble gas mass spectrometry measurements, N-body simulations, collision rate calculations, and impact simulations to estimate the cometary contribution to Vesta.
While our dynamical simulations indicate that Vesta likely underwent a significant number of collisions with large comets, we find no xenon cometary signature in HED meteorites. This apparent contradiction arises due to the fact that cometary impacts were at high speeds and Vesta’s weak gravitational attraction made it incapable of retaining cometary material.
Smaller asteroids are even less likely to retain such material. Therefore, if a cometary xenon signature is ever detected in an asteroid belt object, it must have been acquired during formation, within the same source region as comet 67P/Churyumov-Gerasimenko, and have been implanted later into the asteroid belt.
Sarah Joiret, Guillaume Avice, Ludovic Ferrière, Zoë M. Leinhardt, Simon Lock, Alexandre Mechineau, Sean N. Raymond
Subjects: Earth and Planetary Astrophysics (astro-ph.EP) Cite as: arXiv:2507.00753 [astro-ph.EP] (or arXiv:2507.00753v1 [astro-ph.EP] for this version) https://doi.org/10.48550/arXiv.2507.00753 Focus to learn more Related DOI: https://doi.org/10.3847/PSJ/ade990 Focus to learn more Submission history From: Sarah Joiret [v1] Tue, 1 Jul 2025 13:57:44 UTC (350 KB) https://arxiv.org/abs/2507.00753 Astrobiology, Astrochemistry, Astrogeology,
Sea spiders (Pycnogonida) have a very strange body shape. They’re tiny marine animals with super skinny trunks and legs so long that some of their organs stretch into them! Their belly is so reduced it’s barely visible. They belong to the same group as spiders and scorpions: chelicerates, named after their special claw-like mouthparts called chelicerae.
Because sea spiders look so different, researchers are exploring their genome to understand what genes create such unusual bodies and what this reveals about their evolutionary history.
Researchers from the University of Vienna and the University of Wisconsin- Madison have created the first chromosome-level genome of the sea spider Pycnogonum litorale. This breakthrough helps explain the species’ unusual body structure and offers new insights into the evolution of chelicerates—a group that includes spiders, scorpions, and horseshoe crabs.
To assemble the sea spider genome, researchers used two advanced sequencing techniques. First, they applied long-read sequencing to one individual, which captured long stretches of DNA and helped piece together tricky parts of the genome. Then, with a second individual, they studied how DNA is arranged inside the cell, figuring out which pieces sit close together.
Scientists revealed the oldest known scorpion on Earth
By combining these approaches, they successfully built 57 pseudochromosomes, covering nearly the whole genome with high precision. They also added data on gene activity across different developmental stages, giving an even deeper look into how this unique animal develops and functions.
The team mainly focused on the so-called Hox cluster, a gene family that is evolutionarily conserved across the animal kingdom. In arthropods like sea spiders, Hox genes are crucial for defining where different body segments go—head, thorax, abdomen, etc. But their role isn’t limited to creepy crawlies! Across many animal groups, Hox genes act as master regulators, guiding the overall layout during development.
In a fascinating twist, scientists discovered that Pycnogonum litorale, a sea spider, is missing a key Hox gene called abdominal-A (Abd-A), a gene normally responsible for shaping the rear end of arthropods. Its absence may explain why sea spiders have extremely reduced abdomens, a trait also seen in mites and barnacles.
This supports a broader evolutionary pattern: when certain Hox genes disappear, the body parts they control often shrink or vanish. Sea spiders now join the list of species showing this gene-body connection.
Unlike spiders and scorpions, which show signs of ancient whole-genome duplications, P. litorale has no such genetic echoes. Since sea spiders are considered the sister group to all other chelicerates, this suggests that genome duplications occurred later, in specific subgroups, not in the earliest chelicerate ancestors.
The newly completed genome of P. litorale gives scientists a powerful tool for comparing chelicerate species—like spiders, scorpions, and horseshoe crabs—and studying how their body plans evolved.
Identifying the genes behind venom production
Why sea spiders stand out:
Their development may reflect how early arthropods grew.
They have unique body features not seen in other species.
They can regenerate parts of their body, which is rare and exciting for research.
With the genome and gene activity data now in hand, researchers like Georg Brenneis can explore these traits in detail at the molecular level.
Journal Reference:
Papadopoulos, N., Kulkarni, S.S., Baranyi, C., et al. The genome of a sea spider corroborates a shared Hox cluster motif in arthropods with a reduced posterior tagma. BMC Biol 23, 196 (2025). DOI: 10.1186/s12915-025-02276-x
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Can animals share the same space peacefully high above the ground in the treetops? A research team at the University of Göttingen has found that forests combining both deciduous and conifer trees make it easier for red squirrels and dormice to coexist. Using cameras placed high in the canopy, scientists discovered that red squirrels tend to prefer coniferous forests, while dormice are more commonly found in beech forests. However, in mixed forests that include both tree types, both species were observed living side by side. This suggests that mixed forests could play an important role in supporting biodiversity. The findings were published in the European Journal of Wildlife Research.
The study took place in northern Germany and used 80 cameras placed between 2 and 30 meters above the ground in the trees. The researchers, with the help of professional climbers, had to climb up each tree to install, inspect and retrieve the cameras in the forest canopy. Cameras automatically recorded animals, being activated by movement and heat when animals passed through their field of view. During seven months of observation in 20 different forests, the researchers recorded 468 sightings of red squirrels and 446 of dormice. Among the dormice sightings were 249 edible dormice and 197 hazel dormice. These observations allowed the team to analyze how the presence of each species was linked to the number of beech trees and the presence of other tree-dwelling mammal species.
“Our results show that dormice and red squirrels are not avoiding each other. In fact, they can live together quite well in mixed forests,” says lead author Pedro Mittelman, a PhD researcher in Wildlife Sciences at the University of Göttingen. “This is great news – it shows that forestry management systems combining tree species can benefit wildlife.” The research team highlights the value of cultivating a mixture of trees as a way to support biodiversity, even in areas managed for timber production.
This study is part of the graduate programme EnriCo (“Enrichment of European beech forests with conifers: impacts of functional traits on ecosystem functioning”) at the University of Göttingen. It is funded by the German Research Foundation (DFG) and contributes to ongoing efforts to better understand the functioning of pure and mixed forest ecosystems.
Reference: Mittelman P, Pineda M, Balkenhol N. Mixed broadleaf-conifer forests promote coexistence of red squirrels and doormice. Euro J Wildlife Res. 2025. doi: 10.1007/s10344-025-01947-y
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A sneak preview of the first batch of deep space imagery from the new Vera C. Rubin Observatory in Chile made its way to news sites and social media last week, followed by a livestream event.
“(The Rubin Observatory is) going to build the greatest time-lapse movie of the cosmos ever made,” the observatory said in a post.
The observatory is named for the American scientist widely credited for finding some of the first evidence of dark matter, with the project being funded by the National Science Foundation and the US Department of Energy’s Office of Science.
The scientists and officials from the NSF and DOE participated in a news conference and Q&A about the findings last week. You can watch the stream below.
Millions of galaxies, big images
Though the livestream was plagued by a few technical issues, it still offered some context on what data is being captured at the Rubin Observatory and why.
“Starting today, our ability to understand dark matter, dark energy and planetary defense will grow even faster than ever before,” said Brian Stone, the NSF’s chief of staff.
The observatory’s 3,200-megapixel camera is used for a full-sky scan that happens every three to four days. Stunning images that the observatory shares are only a fraction of what is being captured, in some cases showing only 2 percent of the full view, which would require 400 HDTVs to show.
One image can capture 10 million galaxies. Closer to Earth, astronomers have discovered 1 million asteroids in our solar system and expect to discover 5 million more in the next few years.
During this upcoming week, skywatchers across most of the U.S. and southern Canada will get an opportunity to view the two largest space vehicles now in orbit around the Earth within minutes of each other.
They are the International Space Station (ISS) and China’s space station, Tiangong. If you are up during the predawn hours, you’ll probably be able to make a sighting of both within less than a half hour of each other.
And on the morning of July 5, it may be possible to see both in the sky at the same time.
Night lights
If you go out and carefully study the sky near dusk or dawn, the odds are that you should not have to wait more than a few minutes before you see one of the more than 30,700 satellites now in orbit around Earth.
Most of these are just “space junk” ranging in size from as large as 30 feet (9 meters) down to about the size of a softball, including defunct satellites, rocket bodies, and fragments from collisions. In addition to the tracked objects, there are an estimated 130 million pieces of debris too small to be tracked. U.S. Space Command, headquartered at Peterson Space Force Base in Colorado Springs, keeps a constant watch on all orbiting space debris.
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(Image credit: Amazon)
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Most satellites are too faint to be seen with the unaided eye. But depending on who’s counting, about 500 can be seen with the unaided eye. These are the satellites that are large enough (over 20 feet, or 6 m) in length) and low enough (100 to 400 miles, or 160 to 640 kilometers) above Earth to be most readily seen. In his book Observing Earth Satellites, the distinguished British scientist Desmond King-Hele perhaps said it best: “A satellite looks like a star that has taken leave of its senses and decided to move off to another part of the sky.”
The International Space Station is by far the biggest and brightest of all the man-made objects orbiting Earth. More than four times as large as the defunct Russian Mir space station, the ISS has a total mass of approximately 925,000 pounds (420,000 kilograms), and measures 357 feet (109 m) across and 240 feet (73 m) long. This makes it almost the equivalent to the length of a football field, including the end zones, according to NASA.
Breaking space news, the latest updates on rocket launches, skywatching events and more!
The International Space Station. (Image credit: NASA)
The ISS draws power from four pairs of solar arrays, which are each 112 feet (34 m) long and 39 feet (12 m wide) — longer than a Boeing 777’s wingspan. Additionally, the ISS is being upgraded with six new, smaller Roll-Out Solar Arrays (iROSAs). These are being installed over portions of the existing arrays. Each new iROSA measures 63 feet (19 m) long by 20 feet (6 m) wide. Despite being smaller, they are more efficient due to technological advancements.
Presently circling Earth at an average altitude of 259 miles (416 km) and at a speed of 17,900 mph (28,800 kph), the ISS takes 93 minutes to orbit Earth and completes roughly 15.5 orbits per day. It can appear to move as fast as a high-flying jet airliner, sometimes taking about four to five minutes to cross the sky. Because of its size and the configuration of its highly reflective solar panels, the space station is now, by far, the brightest man-made object currently in orbit around Earth.
On its most favorable passes, it can appear some 2.5 times brighter than Venus and nearly 40 times brighter than Sirius, the brightest star in the night sky. And, as a bonus, sunlight glinting directly off the solar panels can sometimes make the ISS appear to briefly “flare” in brilliance to as bright as magnitude -8, some 19 times brighter than Venus!
China’s orbiting space station
Besides the ISS, there is another space station orbiting Earth. That’s Tiangong (Chinese for “Heavenly Palace”), a permanently crewed space station operated by China’s Manned Space Agency (CMSA). The chief purpose of Tiangong, according to the CMSA, is to develop and gain experience in spacecraft rendezvous technology and to serve the platform for the next-generation orbit transportation vehicles and technology for future deep-space missions.
Tiangong is smaller than the ISS, in overall dimensions measuring about one-fifth as large. Its total mass is approximately 77 tons (69,900 kg). It measures approximately 180 feet (55 m) in length and contains three modules (the ISS has 16 modules). It orbits Earth at an average altitude of 244 miles (393 km), somewhat similar to the ISS.
And, like the ISS, it is a prominent object when moving across the nighttime sky. On its most favorable passes, it can appear as bright as Venus (magnitude -4.1), though usually it tends to appear closer to magnitude -2 (as bright as Jupiter).
Currently, taking into account both the ISS and Tiangong, there are 14 humans in space.
Viewing windows of opportunity
From now through the final days of July, North Americans and Europeans will have many opportunities to see both the ISS and Tiangong flying over their homes, due chiefly to a seasonal circumstance. Nights are now the shortest, and the time that a satellite in low Earth orbit (like the ISS and Tiangong) can remain illuminated by the sun can extend throughout the night, a situation that can never be attained during other times of the year.
Because both space stations circle Earth about every 90 minutes on average, it’s possible to see them not just on one singular pass, but for several consecutive passes.
And from now through July 8, the ISS and Tiangong will be making morning passes — one to two hours before sunrise — within a half hour or less of each other. And on the morning of July 5, for parts of the northeastern U.S. and eastern Canada, it may be possible to see both in the sky at the same time.
On the morning of July 5, 2025, the International Space Station and China’s Tiangong space station are predicted to be within range simultaneously of skywatchers across the northeastern U.S. and Atlantic Canada. Between roughly 3:56 a.m. and 3:58 a.m. EDT, the ISS will pass to the north of New York, while Tiangong will cruise to the south of New York. (Image credit: Courtesy Joe Rao)
This doesn’t happen too often, due to the fact that their orbital altitudes differ slightly, along with the fact that both space stations circle the Earth at different orbital inclinations: 51.63 degrees for the ISS, compared to 41.46 degrees for Tiangong.
Where and when should you look?
So, what is the viewing schedule for your particular hometown? You can easily find out by visiting one of these two popular web sites: Chris Peat’s Heavens Above or NASA’s Spot the Station.
With Heavens Above, you’ll be able to generate accurate sighting data for both the ISS and Tiangong (as well as other bright naked-eye satellites). You’ll simply need to input your location based on latitude and longitude.
NASA’s Spot the Station app is a great tool for quickly finding upcoming ISS viewing opportunities. Simply pop in the location you wish to know for ISS sighting opportunities and let the widget work its magic. It will tell you the time of the ISS flyover along with how long it is visible, the maximum height it will reach in the sky and which direction it will appear and disappear from your field of view.
Predictions computed a few days ahead of time are usually accurate within a few minutes. However, they can change due to the slow decay of the space station’s orbit and periodic re-boosts to higher altitudes. Check frequently for updates.
Joe Rao serves as an instructor and guest lecturer at New York’s Hayden Planetarium. He writes about astronomy for Natural History magazine, Sky and Telescope and other publications.
The archaeological investigations have revealed wooden frames from the hull of Nossa Senhora do Cabo among the ballast stones. (Image credit: Center for Historic Shipwreck Preservation)
Archaeologists say they’ve found the submerged wreck of a sailing ship captured in 1721 near Madagascar, during one of history’s most infamous pirate raids.
The American researchers, from the Center for Historic Shipwreck Preservation, have investigated the wreck for 16 years and now think it’s the remains of Nossa Senhora do Cabo, a Portuguese ship carrying cargo from India that was attacked and seized by pirates, among them the notorious pirate captain Olivier “The Buzzard” Levasseur.
The wreck now lies on the floor of a small harbor on the island of Nosy Boraha off the northeast coast of Madagascar, which was a hangout known as Île Sainte-Marie during the “Golden Age of Piracy” in the early 18th century. New details of the investigations have been published in the latest issue of Wreckwatch magazine.
The identification of the wreck is “supported by multiple lines of evidence,” the center’s co-founder and director Brandon Clifford, one of the researchers, told Live Science in an email. These include analysis of the structure of the ship from its underwater remains, historical records and artifacts found in the wreckage.
Among them are devotional figurines and objects made from wood and ivory, including one that depicts Jesus’ mother Mary; part of a crucifix; and an ivory plaque inscribed with gold letters that read “INRI.” (According to the Christian gospels, these letters were inscribed by the Romans above the crucified Jesus and stood for “Jesus of Nazareth, King of the Jews” in Latin.)
The researchers think these artifacts were made in Goa, which was then the center of a Portuguese colony on India’s west coast, and were being shipped to Lisbon in Portugal.
Related: ‘Pirate’ shipwrecks that sank in 1710 off Costa Rica are actually remains of Danish slave ships
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Image 1 of 3
(Image credit: Center for Historic Shipwreck Preservation)
A sonar image of the seafloor shows the wreck thought to be that of Nossa Senhora do Cabo. Researchers think there are at least four pirate wrecks in the main harbor on the island of Nosy Boraha, off Madagascar.
(Image credit: Center for Historic Shipwreck Preservation)
A mosaic image of the harbor floor shows overlapping piles of ballast stones from ships’ hulls. The ballast pile from Nossa Senhora do Cabo is at the right.
(Image credit: Center for Historic Shipwreck Preservation)
The island of Nosy Boraha off Madagascar’s northeast coast was once a notorious hangout for European pirates known as Île Sainte-Marie.
Pirate raid
According to records, Nossa Senhora do Cabo(Portuguese for “Our Lady of the Cape”) had left Goa early in 1721 bound for Lisbon, with the outgoing Portuguese viceroy and the Archbishop of Goa both on board.
But the vessel was attacked and captured by a group of pirate ships on April 8, 1721, near the French island of La Réunion (also known as Réunion Island) in the Indian Ocean.
The treasure it carried included ingots of gold and chests full of pearls, according to the researcher Denis Piat in his book “Pirates & Privateers in Mauritius” (Didier Millet, 2014).
Image 1 of 3
(Image credit: Center for Historic Shipwreck Preservation)
Artifacts recovered at the wreck site include gold coins inscribed with Arabic writing and pieces of fine porcelain.
(Image credit: Center for Historic Shipwreck Preservation)
The researchers have recovered several religious figurines and other devotional objects made from wood and ivory, presumably at Goa.
(Image credit: Center for Historic Shipwreck Preservation)
More than 3,300 artifacts have now been recovered from the wreck, but many others are still covered by sand and silt.
Clifford and his colleague Mark Agostini, an archaeologist at Brown University, said the Portuguese ship had already been badly damaged in a storm and had jettisoned most of its cannons to stay afloat; and so it was captured with little resistance.
The viceroy was eventually ransomed, but it’s not known what became of the archbishop. About 200 enslaved people from Mozambique below decks, but there are no records of what happened to them.
According to Clifford and Agostini, the entire haul was “an eyewatering treasure, even by pirate standards,” and the cargo alone may have been worth more than $138 million in today’s money.
Sea dog base
The pirates then steered their captured prize toward Madagascar, about 400 miles (650 kilometers) west of La Réunion, to divide up their loot.
The researchers wrote that Île Sainte-Marie was chosen by European pirates because its sheltered anchorages were close to major shipping lanes. It was also known for its “absence of colonial governance,” making it an ideal pirate base.
Clifford added that between seven and 10 shipwrecks were wrecked or scuttled near Île Sainte-Marie during the Golden Age of Piracy and “at least four pirate shipwrecks or their prizes lie in the harbor itself.”
Agostini, meanwhile, told Live Science in an email that more than 3,300 artifacts had now been recovered from the wreck of Nossa Senhora do Cabo, but that the overlying silt and sand had made further recoveries difficult.
He added that archaeologists had previously overlooked Île Sainte-Marie and the scientific treasures it contained. “Ideally, future fieldwork will lead to more analysis of the many wrecks there,” Agostini said.
Editor’s note: This story was updated at 2:32 p.m. ET to remove a detail about a gold- and ruby-encrusted cross being on the ship at the time of its capture. This cross was mentioned in a book about the shipwreck, but Live Science has since learned that it might be a myth.
An asteroid discovered last year and briefly thought to be a threat to Earth has a one-in-23 chance of hitting the Moon, according to NASA estimates based on JWST data. A new paper outlines how this could be a spectacular one-in-5,000-year event, potentially ejecting material towards Earth.
Asteroid 2024 YR4 was first discovered on December 27, 2024. Astronomers have been keeping a close eye on it ever since, as initial observations showed around a 1 percent chance that it could collide with Earth on December 22, 2032. Follow-up observations of the asteroid briefly showed a higher chance of the asteroid making an impact. At 3.1 percent, it briefly became considered the most dangerous space object since tracking began.
Thankfully, as repeatedly predicted by astronomers during that slightly nervous time, as more observations came in, the chances of impact with Earth fell dramatically, and now stand at around 0.004 percent.
But the Moon may not be so lucky.
“The odds of an impact into the Moon have always been there. It’s been lower at that time because the Earth [was] a bigger target,” planetary scientist Dr Andrew Rivkin, from Johns Hopkins University in Maryland, told IFLScience back in April.
“The way that the orbit improved made the position move away from the Earth, but it moved toward the Moon. So there’s like almost a 4 percent chance it’s going to hit the Moon. That means there’s a better than 96 percent chance it’s going to miss the Moon, but if it did hit the Moon, it really would be pretty spectacular!”
Back then the object had a 3.8 percent chance of hitting our natural satellite, but following further observations by JWST and analysis by NASA’s Center for Near-Earth Object Studies at the agency’s Jet Propulsion Laboratory (JPL) in Southern California, NASA have updated the chance of impact with the Moon on December 22, 2032, to 4.3 percent. On that date, it will pass around 0.00007 Astronomical Units (AU) of the Moon, with 1 AU being the distance between the Earth and the Sun.
Diagram showing the position uncertainty of asteroid 2024 YR4.
Image credit: NASA/JPL Center for Near-Earth Object Studies
While an Earth impact was an intimidating prospect, astronomers are a bit more excited by the prospect of it slamming into our companion space rock. In short, it would be pretty spectacular, potentially even causing a meteor shower on Earth.
“It would be visible from Earth and there would even be new lunar meteorites that would arrive on Earth (nothing dangerous), but there is no guarantee,” Richard Moissl, the head of the European Space Agency’s Planetary Defence Office, told IFLScience back in February. “Definitely, a new observable moon crater would be the outcome!”
NASA stresses that the asteroid hitting the lunar surface would not alter the Moon’s orbit. However, a new study led by Paul Wiegert, professor of physics at the University of Western Ontario, suggests that it could release around the equivalent of 6.5 megatons of TNT in energy, leaving the Moon with a crater around 1 kilometer (0.62 miles) in diameter.
“If 2024 YR4 strikes the Moon in 2032, it will (statistically speaking) be the largest impact in approximately 5,000 years,” the team explains in their paper. “We estimate that up to 108 kg of lunar material could be liberated in such an impact by exceeding lunar escape speed.”
Attempting to model various impacts, the team found that the ejected Moon debris could cause spectacular meteor showers on Earth. While this would be an amazing sight for the layperson, and meteorites making it to the surface of Earth is not ruled out, it could be a nightmare for any governments or organizations with satellites in orbit.
“The lunar ejecta-associated particle fluence at 0.1 – 10 mm sizes could produce upwards of years to of order a decade of equivalent background meteoroid impact exposure to satellites in near-Earth space late in 2032,” the team explains, adding, “the instantaneous flux could reach 10 to 1,000 times the background sporadic meteor flux at sizes which pose a hazard to astronauts and spacecraft.”
“Our results demonstrate that planetary defense considerations should be more broadly extended to cis-lunar space and not confined solely to near-Earth space.”
According to the team, ejected material could pose hazards to the Lunar Gateway, surface operations on the Moon as ejecta falls back towards it, as well as satellites in Earth orbit.
“There is some risk but it depends a lot on exactly where the asteroid impacts, if at all. We will probably know this soon after the asteroid returns to visibility (it’s too far/faint to see at the moment) in 2028,” Wiegert explained to IFLScience. “But I understand that NASA is already considering how to respond, if necessary.”
In short, it would be a spectacular and rare event, that you may even get to gawp at in the form of a meteor shower. The impact itself may be harder to spot, though not impossible.
“If the impact happens on the side of the Moon towards the Earth, the impact will be visible though hard to catch,” Wiegert added. “There will be a brief bright flash followed by a dust cloud that will disperse over a few minutes. But the cloud and the resulting crater (which will be about a km across) will be near the limit of what can be clearly seen from Earth. Spacecraft in orbit will get a much better view.”
With the odds of impact still low, we might not get this space treat. Right now, the asteroid is too far from human telescopes to get a good look at it, but we will get another look at it before it makes its close approach in 2032.
“Asteroid 2024 YR4 is now too far away to be observed with space-based or ground-based telescopes,” NASA explained in a statement. “NASA expects to make further observations when the asteroid’s orbit around the Sun brings it back into the vicinity of Earth in 2028.”
The paper is submitted to the American Astronomical Society and is available on pre-print server arXiv.
Corals are reef-building animals that can’t photosynthesise on their own. Instead, they rely on micro-algae living inside their tissues to do it for them. These symbiotic algae use sunlight, carbon dioxide, and water to produce oxygen and energy-rich sugars that support coral grwoth and reef formation.
At around 10 micro-metres across – about one-tenth the width of a human hair – these algae are far too small to be seen with the naked eye. When corals are stressed by warming waters or poor environmental conditions, they lose these micro-algae, leading to a pale appearance.
This is the process known as coral bleaching. It leads – eventually – to the starvation of the coral. Although this process is known, scientists don’t fully understand why, and it hasn’t been possible to study the process at appropriate scales in the field – until now.
“The microscope facilitates previously unavailable, underwater observations of coral health, a breakthrough made possible thanks to the National Science Foundation and its critical investment in technology development,” said Jules Jaffe, a research oceanographer at Scripps and co-author of the study.
“Without continued federal funding, scientific research is jeopardised. In this case, NSF funding allowed us to fabricate a device so we can solve the physiological mystery of why corals bleach, and ultimately, use these insights to inform remediation efforts.”
Through an array of high-magnification lenses and focused LED lights, the microscope captures vivid colour and fluorescence images and videos. It also now has the ability to measure photosynthesis and map it in higher resolution via focal scans. Scientists can use this to create high-resolution 3D scans of corals.
Working in collaboration with the Smith Lab at Scripps Oceanography, Ben-Zvi – a marine biologist – has tested and calibrated the instrument at several coral reef hotspots around the globe, including in Hawaii, the Red Sea, and Palmyra Atoll.
Throughout her many observations, Ben-Zvis has been most surprised by how active the corals have been, noting that they changed their volume and shape constantly. She even observed instances in which a coral polyp appeared to be trying to capture or remove a particle that was passing by, by rapidly contracting its tentacles.
“The more time we spend with this microscope, the more we hope to learn about corals and why they do what they do under certain conditions,” said Ben-Zvi. “We are visualising photosynthesis, something that was previously unseen at the scales we are examining, and that feels like magic.”
The non-invasive technique allows researchers to assess the health of corals without the need to interrupt nature – it’s similar, Ben-Zvi has said “to checking on the coral’s pulse without giving them a shot or doing an intrusive procedure on them.”
The researchers have also said that data collected with the new microscope can reveal early warning signs that appear before corals experience irreversible damage from global climate change events, such as marine heat waves. These insights could help guide mitigation strategies to better protect them.
Beyond corals, and the tool has other widespread potential for studying other small-scale marine organisms that photosynthesise, such as baby kelp. In fact, several researchers at Scripps Oceanography are already using the BUMP imaging system to study the early life stages of the exclusive giant kelp off California.
“Since photosynthesis in the ocean is important for life on earth, a host of other applications are imaginable with this tool, including right here off the coast of San Diego,” said Jaffe.
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Not one, but two exploding stars are currently visible to the naked eye in the southern night sky, a cosmic coincidence that’s “exceedingly rare” and may soon vanish from view entirely.
On June 12, the All-Sky Automated Survey for Supernovae (ASAS-SN), led by the Ohio State University, detected a dramatic surge in the brightness of an otherwise unremarkable star embedded in the constellation Lupus. Subsequent observations revealed a powerful nova explosion — now designated V462 Lupi — to be the cause of the radiation outburst. The star quickly brightened from its previously dim magnitude of +22 to a peak brightness of around +5.5, rendering it visible to the naked eye.
Remember, magnitude is the system used by astronomers to track the brightness of an object in the night sky. The lower the magnitude, the brighter the object! The human eye is capable of detecting stars with a magnitude of around +6.5 or greater in dark sky areas.
Less than two weeks later, on June 25, reports began to circulate of a second nova blossoming in the southern night sky, this time in the constellation Vela. This nova — later designated V572 Velorum — quickly jumped to a similar peak of +5.5, making it appear as if two new stars had suddenly burst to life in the skies south of the equator.
A nuclear explosion on the surface of a star
“Both appear to be part of binary star systems composed of a white dwarf and a companion star,” veteran science communicator and meteorologist Joe Rao told Space.com in an email. “In each case, the objects that we are able to see visually, are likely being caused by a thermonuclear explosion on the surface of the white dwarf star.”
These kinds of explosions are called novas. Unlike,their more violent cousins, supernovas, these events don’t destroy the star. Instead, they occur as a result of a vampyric process in which the gravitational influence of a white dwarf strips material from a nearby companion star, adding it to its own mass. This ‘feeding’ continues until the mass of stolen stellar material deposited on the surface of the white dwarf is heated to a critical threshold, after which a cataclysmic thermonuclear explosion is inevitable.
The resulting outpouring of radiation leads to a dramatic increase in a star’s apparent brightness from our perspective on Earth, occasionally making it appear as if a new stellar body has burst to life in the night sky.
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A comparison of two nova explosions and the difference in their luminosity. (Image credit: Eliot Herman)
“To have two naked-eye novae shining in the sky at the same time is an exceedingly rare event”
“To have two naked-eye novae shining in the sky at the same time is an exceedingly rare event,” said Rao. “In checking my copy of Norton’s Star Atlas, which lists bright novae dating back to the 16th century, I can only find one other case of two novae erupting so close together: V368 Aquilae on September 25, 1936 and V630 Sagittarii just eight days later.”
Rao — who serves as an instructor and guest lecturer at New York’s Hayden Planetarium — went on to note that the 1936 novas had faded swiftly after reaching their peaks and likely wouldn’t have been visible simultaneously. Astronomer Stephen James O’Meara also discovered a 2018 occurrence in which two novas peaked and became visible to the unaided eye on the same day, according to stargazing website Earthsky.org.
Where to find the novas in the southern sky
“Generally speaking, most novae fade from view after a few weeks, although some may fade much faster (as was the case with the aforementioned novae in 1936) and sometimes the fade-down may take longer,” said Rao. “In the case of V572 Velorum, it apparently exhibits both long (over 13 days) and short (3-4 days) outbursts.”
The location of the V462 Lupi nova shown close to the constellations Lupus and Centaurus. (Image credit: Created in Canva by Daisy Dobrijevic)
It may still be possible to spot the ancient light from both novas from a dark sky location for observers in the southern hemisphere. Meanwhile, those in the southern U.S. might yet glimpse V462 Lupi peeking above the horizon — perhaps with the aid of a pair of 10X50 binoculars.
The patch of sky containing V462 Lupi is located in the constellation Lupus, close to the bright stars Delta Lupi and Kappa Centauri, from the neighboring constellation Centaurus. Lupus will be highest in the sky for those in the southern hemisphere, though those in the southernmost states of the U.S. may spot the constellation — and the site of the nova — close to the southern horizon at sunset in early July.
A star chart showing the location of the V572 Velorum nova alongside stars from the constellation Vela. (Image credit: IAU and Sky & Telescope, annotations by Anthony Wood)
V572 Velorum meanwhile, can be found in the southern constellation Vela and is not easily visible from the continental United States. Viewers in the southern hemisphere will find the region of sky containing the nova close to the bright stars Mu Velorum and Phi Velorum.
If you do manage to catch even a fleeting glimpse of either V572 Velorum, or V462 Lupi, you will have witnessed first hand one of the most spectacularly violent explosions that the universe has to offer. Not bad for one evening’s stargazing.
Editor’s Note: If you capture an image of a nova and want to share it with Space.com’s readers, then please send your photo(s), comments, and your name and location to spacephotos@space.com.
