NASA's Mars rover Curiosity spotted these "honeycomb" structures on Mars. (Image credit: NASA/JPL-Caltech/MSSS)
NASA's Curiosity rover has spotted a strange honeycomb texture on the surface of Mars. But what is it?
What is it?
Almost 14 years since landing on the Red Planet, Curiosity is still hard at work exploring. And in new observations, Curiosity has revealed an image that is certainly ... peculiar.
Curiosity went to get a closer look at an area first observed from Mars orbit, and found what appears to be a honeycomb structure in on the planet's surface. Polygonal shapes, nearly identical to one another, make up a pattern almost like a Martian wallpaper or carpet.
But what is it? Why does it look like that? What is a honeycomb doing on Mars?
Why is it incredible?
This is one of many mysteries we have yet to solve on Mars. While the team saw this area first from orbit around the planet, when the rover arrived and saw this structure they were surprised, they shared in a blog post.
In addition to the honeycomb texture, the area was littered with dark rocks and strewn around. But even these pebbles lack explanation. Did they "float" down from higher rock levels, did they launch out of Gale crater during some ancient collision or could they possibly even be meteorites from outside of Mars that ended up strewn across the surface? Researchers think any one of these explanations could be possible.
Previous, similar dark stones have been found on Mars with minerals like nickel that are common in meteorites and uncommon in Mars rocks. But are these similar? Perhaps part of a similar collision event? We don't yet know.
As researchers find new mysteries on Mars, they also continue to find new ways to investigate the unknown. With further study, they will explore both these strange honeycombs and the dark rocks scattered amongst them.
Landing spacecraft on the moon could contaminate ancient clues about how life may have originated on Earth, a new study finds.
As NASA continues on with its plan of sending astronauts back to the moon with the Artemis program, researchers are exploring what possible unintended consequences may arise from humans visiting the lunar surface. For instance, Artemis IV will land astronauts near the moon's south pole and the agency has future plans for building a longer-term moon base on the lunar surface, which would require many more trips. And indeed, a new study has found the exhaust from spacecraft involved with these landings could expel enough methane to contaminate the moon's surface — possibly destroying molecules that could help to explain how life may have originated on Earth.
"We are trying to protect science and our investment in space," senior study author Silvio Sinibaldi, the planetary protection officer at the European Space Agency, said in a statement. "Our activity can actually hinder scientific exploration."
While experts have had concerns for some time about how rocket launches on Earth pollute our planet and atmosphere, scientists have only really considered this issue with our own planet. This is especially because we haven't been to the moon's surface in over 50 years; concerns of accidental effects of a lunar landing simply haven't been top-of-mind. That's what makes this new study so important. It points to a potential issue that could mean that future moon landings might actually be detrimental to science.
An artist's concept of Blue Origin's lunar lander. Lunar landings could pose a serious issue for science on the moon if methane contaminates ancient polar ices, a new study has found. (Image credit: Blue Origin)
Life's clues on the moon?
So why do we think the signs of life could be hiding on the moon? It's actually hiding in ice. Dark craters near the moon's poles, which exist in perpetual shadow, hold ancient ice. This ice is thought to contain material from asteroids and comets that smashed into the moon billions of years ago. Trapped in lunar ice to this day, these bits of ancient collisions could include what the researchers describe as "prebiotic organic molecules," or molecules that could have preceded life on Earth.
It's thought that these molecules from asteroid and comet visitors could have sparked life on Earth, and by studying those possibly trapped on the moon, researchers could be looking at the molecules that ended up combining and creating life as we know it.
The molecular history of life on Earth is pretty much nonexistent on our own planet, as it was largely destroyed by the billions of years of changes we've experienced. But the moon has remained mostly unchanged, so these wells of ice are a uniquely-preserved sampling of pre-life molecules.
"We know we have organic molecules in the solar system — in asteroids, for example," Sinibaldi said. "But how they came to perform specific functions like they do in biological matter is a gap we need to fill."
This ice exists in a somewhat fragile ecosystem, so left alone in darkness, this ice isn't going anywhere anytime soon. But with Artemis, NASA is planning on sending crewed landers to the moon's south pole. That might pose a problem. With computer models in this new study, researchers have shown that the methane exhaust from these landers could very quickly and permanently contaminate this ancient ice, destroying the molecular evidence sealed within.
Inside the simulations
This image shows the distribution of surface ice at the moon’s south pole (left) and north pole (right). Blue represents ice locations, and the gray scale corresponds to surface temperature, with darker gray representing colder areas and lighter shades indicating warmer ones. (Image credit: NASA)
In those computer models, the researchers simulated how methane, the main organic component expelled by planned lunar landers, would spread across the moon's surface after a landing at the south pole. While the simulations included the effects of solar wind and radiation, the moon's lack of an atmosphere caused the methane to spread incredibly quickly, reaching the moon's north pole in under two lunar days.
Within one lunar week (which is roughly seven months on Earth), over half the methane was trapped at the moon's cold polar areas, with a whopping 42% of the substance trapped at the south pole compared to 12% at the north pole. This methane could collect in the same cold pockets where ice and ancient molecules have been collected for billions of years, possibly contaminating this finite, scientific evidence.
"Their trajectories are basically ballistic," lead author Francisca Paiva, a physicist at Instituto Superior Técnico in Portugal, said in the statement. "They just hop around from one point to another."
In better news, there may be a way to circumvent some of this methane disturbance. For instance, the study suggests it's possible that by choosing colder landing sites, scientists can avoid having the methane travel as quickly or as far. Additional simulations are needed to better understand how exhaust compounds travel on the moon, however, as well as the risks that this poses for scientific investigations and if there are other materials lunar trips will involve that could contaminate the environment. Above all, the new study's team emphasizes that as we push toward future lunar exploration, it is key to balance our dreams of settling the moon with preserving its priceless history.
"We have laws regulating contamination of Earth environments like Antarctica and national parks," Paiva said. "I think the moon is an environment as valuable as those."
Environmental and scientific organizations are banding together to demand federal environmental reviews of space-based data center projects, which plan to put more than a million new satellites in Earth orbit over the coming years.
Over the last few months, a number of different companies have requested licenses from the U.S. Federal Communications Commission (FCC) to launch data centers into space. SpaceX's proposal alone requests licenses for up to one million satellites in low Earth orbit (LEO). But the requested licenses don't come with any environmental review of the impacts that the satellites — especially collectively — could have on dark skies, wildlife or our atmosphere. In response, a coalition of environmental and scientific organizations represented by the environmental nonprofit Earthjustice have petitioned the FCC for this review.
"Allowing a million orbiting data centers with no environmental review isn’t just irresponsible — it’s reckless," Tim Whitehouse, executive director of Public Employees for Environmental Responsibility, said in a statement on Wednesday (July 8). "The potential for these projects to degrade the atmosphere with pollution and debris and harm wildlife needs to be carefully considered before licensing these projects."
Space is big, but a million new satellites added to LEO to support space-based data centers would be a massive increase. Currently, just Earth orbit harbors just 15,000 active satellites and 46,000 tracked objects overall. This number was already on track to grow to 58,000 active satellites, thanks in large part to SpaceX's ever-growing Starlink broadband megoconstellation, but the data-center plans could make it absolutely explode.
Experts suggest that this significant addition to the technological ecosystem in orbit could have disastrous consequences for life on Earth.
"Drastically expanding satellites in space has a direct impact on people’s everyday lives as well as the future of our planet," Jan Hasselman, senior attorney at Earthjustice, said in the statement. "Agencies that authorize companies looking to space as the next frontier still must operate within the law, and the law requires the FCC to consider all the risks and impacts of these proposals. If we have to sue so that they comply, we will."
The FCC has not yet required any environmental review for satellite companies seeking authorization to deploy in LEO. With its new petition, this coalition aims to change that, asking the FCC to stop granting licenses for orbiting data centers without an environmental review.
What possible environmental harms are they worried about? First of all, as more and more satellites are added to the orbital population, the greater chance there is of collisions, which could produce debris that not only clutters Earth orbit but also increases the risk of additional collisions.
Further the rocket launches that propel the satellites to orbit contribute greenhouse gas emissions to our atmosphere. And the spacecraft cause further pollution when they deorbit, releasing heavy metals and other materials when they burn up in Earth's air.
In addition, a massive increase in satellites will fundamentally change the night sky. Light pollution is known to impact wildlife and ecosystems, disrupting natural rhythms and influencing everything from migration patterns to daily feeding schedules. These disruptions can push animals like bats to miss windows in which insect prey are available, causing them to starve. They can also prevent mountain lions — apex predators that uphold their local ecosystems — from roaming normally at night, fragmenting populations over time, according to the National Wildlife Federation.
The effects of light pollution on wildlife would doubtless grow if suddenly a million new, blinking satellites were added to our night skies. And issues with light pollution extend to our species as well, as life would look quite different if our night skies were much more crowded by bright lights.
"These projects could permanently alter the night sky as we know it," Ruskin Hartley, executive director of DarkSky International, said in the statement. "The FCC needs to take seriously its obligation to ensure these projects do not cause unnecessary harm to naturally dark skies, or to our overall environment."
Sandbars and waves of rippling sand dunes can be seen from space amongst the turquoise ocean in the Bahamas. (Image credit: NASA/Chris Williams)
If you look at this picture for too long, you might start to hear the waves lapping up against the shore or feel a salty breeze in the air.
You might not have a trip to the Bahamas planned, but you can always enjoy its beauty in this spectacular summertime snapshot captured by NASA astronaut Chris Williams from aboard the International Space Station.
What is it?
In a snapshot that looks straight out of a travel commercial, we can see the crests of rippling waves of sand peeking out from beneath turquoise waters off the coast of the island Eleuthera in the Bahamas.
The moment was captured 263 miles (423 kilometers) above Earth's Atlantic Ocean from aboard the space station orbiting our planet.
This isn't the first fun snapshot captured by Williams who also recently flexed his muscles for a photo mid-spacewalk.
Why is it incredible?
This photo is incredibly beautiful. That much is immediately obvious. And if you've ever swam in picturesque waters like this, then you know how calming and magical such places on Earth can be.
But this photo is more than just pretty, as it shows that we can see Earth's beauty from 263 miles away. It is a reminder that our planet is truly special. Imagine if a future mission saw beauty like this from space on a far off exoplanet, or even a planet outside of our solar system. Currently, our planet is the only one we know of with views like this, but it's possible that in the future we might find tropical shorelines and vacation vistas aren't exclusive to our home planet.
The success of NASA's future moon base depends in large part on mission design, which should allow astronauts to work together well in a way independent from psychological training, a new study asserts.
The goal of the study was to identify "specific conditions" for mission success and to look for any "red flags" that may stand in the way, lead investigator Anamaria Berea, a computational social scientist at George Mason University (GMU), told Space.com via email. (The first author of the PLOS ONE study, which was published in May, was GMU's Raymond Vera.)
The team conducted the research using agent-based models, which are tools for computational simulations in fields ranging from the study of bird flocks to the spread of disease, Berea said. While a lot of modern-day AI "trains" or "learns" to extrapolate from information provided in a data set, agent-based modeling instead uses a data set to "understand emergent phenomena that don't have one single cause or direct cause," she said.
The study team considered scenarios for how many astronauts would be on the moon base and how often resupply missions would occur. In an "initial case," for example, the assumed mission duration was three months, with a single resupply run at Month 2 with food, water, air and a fresh group of astronauts.
Using a complex probability analysis known as a Monte Carlo simulation, the model astronauts in this scenario showed a productivity rate of about 20% against their expected tasks, "which is acceptable for a typical manufacturing process," the authors noted.
This productivity rate doesn't take into account anything unexpected that may crop up during the mission, the authors added. "The low task completion rate suggests that, on average, teams are having challenges to overcoming psychological stressors and environmental disruptions," they wrote.
Lessons from the International Space Station
NASA tracks productivity a little differently on the International Space Station (ISS). The agency uses a metric called "utilization," which largely refers to the amount of crew time and number of scientific investigations that are performed on the space station during an increment or expedition. As of 2014, the ISS program suggested that ideal utilization should be 35 hours per crew per week when there are three people working on the U.S. part of the space station, and 68.5 hours if there are four or more. (The Russian side of the ISS works largely independently in this respect.)
"NASA has generally met or exceeded this goal and set a high of 120 average hours per week devoted to research from October 2019 to April 2020," NASA's Office of the Inspector General (OIG), which has been tracking all of these productivity figures, stated in a report published in September 2024.
"Starting March 2022 through March 2023, the latest published data, we have seen utilization near 90 hours per week," the OIG noted. "In addition to the hours spent per week on research, the number of scientific investigations performed on-orbit has increased."
Figure 1 of the OIG report also shows both crew time and scientific investigations increasing, as a trend, between 2000 and 2023, suggesting that utilization of the space station is continuing to grow. And this is despite periodic and documented disruptions that required astronauts to take a step back from being productive, such as emergency ammonia leaks requiring spacewalks, the 9/11 disaster, or sheltering in place during brief contingencies such as space debris passing within a few miles of the station.
Not all crew time can be used for utilization even if all goes well, however, as the station requires normal maintenance like cleaning, and astronauts also need daily time for sleep, meals and a little relaxation. Additionally, utilization tends to increase with larger crews on the space station compared with smaller ones, as maintenance becomes less of a burden with more hands to take on these tasks.
But "lack of redundancy" in key supply items to the space station does pose a risk to utilization, the OIG has noted. As just one example, SpaceX Crew Dragon capsules and Roscosmos Soyuz spacecraft are the only two vehicles that bring astronauts to the station right now. "The lack of redundancy and limited capabilities of both cargo and crew transportation increase the risk to NASA's current and future ability to bring critical supplies, science, and crew to and from the station to maintain safe operations and full utilization of the ISS," the OIG wrote in the report.
An artist’s concept of astronauts working on the lunar surface. (Image credit: NASA)
Isolated environments
Those of us who have been on long car rides in a group, or who remember being in tight quarters with roommates or family during the pandemic, have some idea of what an isolated, confined environment (ICE) feels like: crowded, with limited resources, and possessing few connections with the outside world. Space serves as just one example of a true ICE; isolated research bases (like in Antarctica) or submarines have also been studied in the literature, according to a separate 2021 study in the journal Neuroscience & Biobehavioral Reviews.
Put simply, ICE refers to a location where humans must work to a high standard in isolated and often dangerous circumstances, with only long-distance support (if possible) from a mission control or its equivalent. And, as the new study points out, a moon base would be a complex example of an isolated environment — one featuring not only resident astronauts but also rovers, other robots and occasional visiting crews.
"The premise for our modeling approach came from trying to understand better the human factors involved in crewed space missions, particularly the deep-space ones, for which we don't have a lot of historical data," Berea said.
That's because only a handful of people have traveled beyond low Earth orbit — the two dozen who flew to lunar realms on Apollo missions in the late 1960s and early 1970s, and the four astronauts of NASA's Artemis 2 flight around the moon this past April.
"We ran various scenarios of space mission durations, number of astronauts, potentially unforeseen circumstances that can happen on the lunar surface or the habitat," she said. The model suggested the missions with the highest probability of success would include six astronauts working on the moon at a time, with fresh supplies coming from Earth every two weeks, and no extreme fluctuations in the environment from things like radiation or a micrometeorite impact.
"In contrast, the worst-case scenario consists of four astronauts on the moon at one time, only one month resupply window between Earth and moon, and moderate to high adverse environmental probabilities," Berea said. And, when asked if training is a factor in mitigating adverse effects, she did not necessarily agree that the years of work NASA and other agency astronauts put in would be more effective than shorter-duration training used for moon base analogs.
"People can be very, very well trained, but for long-duration or deep-space missions, there will always be a human factor involved," she said. "We looked at combinations of skills and personalities in a team of astronauts, and there is a fine line between having a team that is too small and a team that is too large, and there are synergies and emergent behaviors that come from people interacting with each other and with their environment.
"The team is more than the sum of its people," she continued. "The best ways to overcome these is not by more training, but by fine-tuning other aspects of the missions: the duration of the mission, the frequency of resupply missions, and the contingency plans for accidents and unforeseen conditions in extreme environments."
NASA, however, puts its ISS crews through many years of remote environment training long before they float through the space station hatch — and Artemis 2 commander Reid Wiseman told The New Yorker that extensive psychosocial training led to the obvious closeness seen live among his own four lunar crewmates despite tight quarters (and vent line issues that led to occasional toilet trouble).
That psychological intervention during training was by design. "Preparation starts by recruiting mentally healthy people and then providing training to help them deal with potential situations and issues," wrote the Canadian Space Agency of this training, citing NASA protocols. "Astronauts repeat this training often enough that they can anticipate their own reactions and those of their teammates. They also receive constant support from teams on the ground and have access to a variety of tools to help them deal with potentially difficult situations."
Berea noted, however, that psychology forms a part (but is not the focus) of her teams' simulation, including considering NASA TLX (task load index) scores and data, which measures coping and stress for astronauts. The researchers also considered case studies from analogs including Antarctic research missions and time aboard submarines or oil rigs, as some examples.
"We need to pay attention not only to the astronauts, but the team as a whole, and each team and space mission are unique. We will not be able to model these with statistics or AI," she said. "But what we can do is to make sure that before we send any human to live and work on the moon, that we understand well the complexity of interactions and scenarios they will face during the mission, and we can help with that."
For decades, astronomers have debated whether Earth's fate was tied to the sun's. When the star exhausts the hydrogen fuel that powers it about 5 billion years, it will swell into a red giant large enough to engulf Mercury and Venus — and, several studies have suggested, Earth as well.
New research, however, suggests our planet has a better chance of escaping that fiery end than previously thought. Using updated models of how aging stars interact with their planets, researchers found that the gravitational forces drawing Earth toward the expanding sun are weaker than older models predicted. That would give the planet more time to drift outward as the dying sun sheds its outer layers into space, potentially avoiding engulfment altogether.
The finding does not guarantee Earth's survival. Instead, researchers say it shifts the biggest uncertainty from how strongly the expanding sun tugs on planets to the poorly understood variable of how much mass the star will lose during its final stages of evolution.
"The largest uncertainty no longer comes from the tidal calculations, but from how much mass the future sun will lose," study lead author Mats Esseldeurs of the KU Leuven's Institute of Astronomy in Belgium said in a statement. "Observations of sun-like giant stars currently point towards Earth's survival, but we need better observations before we can be certain."
When stars like the sun exhaust their core hydrogen and balloon into massive red giants, they trigger a cosmic tug-of-war between expanding tidal forces pulling planets inward and shedding stellar weight pushing them outward, which ultimately decides whether nearby worlds are engulfed or saved.
This planetary push-and-pull unfolds in two stages. As the sun expands, gravitational tides act like a subtle brake, slowly draining Earth's orbital energy and pulling the planet inward. At the same time, the dying star sheds vast amounts of gas through powerful stellar winds, eventually losing about half its mass. As the sun grows lighter, its gravitational grip weakens, pushing the surviving planets outward into a wider orbit that could double their distance from the star, according to NASA.
"The fate of Earth depends on a delicate balance between these two effects," Esseldeurs said in the statement. "If tidal interactions dominate, Earth is engulfed. If mass loss dominates, Earth escapes to a wider orbit."
Previous studies reached different conclusions mostly because they treated those competing processes differently, Esseldeurs and his team argue. A few of those studies neglected tidal interactions altogether, while others relied on simplified prescriptions developed decades ago that predicted a much stronger inward pull, according to the study.
Instead of relying on those older formulas, the new study uses updated calculations of tidal forces based on the shifting internal structure and dynamics of aging stars — which the team says allowed it to precisely account for both tidal friction and shifting stellar winds — before testing the results against a range of possible mass-loss rates for the sun's final giant phase.
The results suggest that even with the weaker inward gravitational pull, Mercury and Venus are unable to outpace the expanding sun and are inevitably engulfed, while Earth and Mars migrate safely through both giant phases, leaving our planet to eventually settle into a broader orbit around the white dwarf remnant the sun will leave behind, the study found.
A schematic evolution of the sun as it goes through its giant phases. The image showed the sun as it is today, going through its two giant phases, before ending its life as a white dwarf. The study showed that Mercury and Venus will be engulfed by the expanding sun, but Earth and Mars survive, ending up in a wider orbit. Sizes and distances are not to scale. (Image credit: Institute of Astronomy of KU Leuven)
The picture is far from settled, however. Because astronomers still cannot precisely observe how rapidly sun-like stars lose mass late in life, "the ultimate fate of the Earth remains uncertain," the researchers write in the new paper.
By factoring in real-world mass-loss rates from L2 Pup — a red giant star roughly 183 light-years away that was used as a proxy for our future sun due to its similar mass — the researchers confirmed that Earth will drift outward just quickly enough to avoid being swallowed, tipping the scales toward survival over destruction, the study notes.
For us humans, the finding offers academic comfort rather than practical salvation. Most scientists agree that as the sun ages, it will steadily grow hotter, boiling Earth's oceans and rendering the planet completely uninhabitable in about 1 billion years, long before the sun begins to expand.
Yet even if humans aren't around to witness it, tracking Earth's ultimate survival provides important context for how planetary systems evolve as their stars age, a framework that researchers say will be further refined by future observations of dying, sun-like stars.
"This will enable us to conduct population studies of the planetary orbital evolution around evolved stars," the researchers wrote in the paper, "and help us to constrain the future evolution of the Earth-sun system."
The study was published in June in the journal Astronomy & Astrophysics.
The mystery of how the sun's corona, which is its outer atmosphere, reaches millions of degrees could have a surprising explanation: cosmic dust riding the magnetic waves carrying plasma on the solar wind.
"For decades, researchers have focused mainly on how electrons, ions, magnetic fields and plasma waves transport and dissipate energy in the solar atmosphere," said lead researcher Syed Ayaz of the University of Alabama in Huntsville in a statement. "Our work adds a new ingredient to this picture: dust grains."
The finding came courtesy of NASA's Parker Solar Probe, which has flown closer to the sun than any other spacecraft, skirting the corona at a distance of 6.1 million kilometers (3.8 million miles). If you've ever witnessed a total solar eclipse, or even seen a photograph of one, then you will be familiar with the corona — the ghostly tendrils of light that surround the eclipsed sun. Those tendrils are formed from plasma, or ionized gas, at temperatures in excess of a million degrees Fahrenheit, compared to the sun's visible surface, the photosphere, which radiates at about 9,932 degrees Fahrenheit (5,500 degrees Celsius). At those temperatures, the photosphere outshines the corona only because the plasma in the corona is so sparsely distributed. This is why the only time we can see the corona is during a total solar eclipse, when the photospheric glare is blocked.
Parker does not carry a cosmic dust detector, and that's because until now dust has not been considered a serious component of the solar atmosphere. Indeed, in the high temperatures of the solar corona it had been thought that dust could not survive for very long and would therefore have no impact.
However, Parker does host a bunch of antennas and magnetometers collectively referred to as the FIELDS experiment, designed to measure the electromagnetic field and radio emissions in the solar corona. The antennas kept picking up unexpected spikes in voltage, which according to Ayaz and his team are produced by clouds of charged particles created when tiny dust grains slam into Parker at high velocity.
These dust grains have accrued an electrostatic charge, which can interact with the electromagnetic field carried by the solar wind as it leaves the sun, which in turn can influence waves of plasma reverberating through that electromagnetic field called Alfvén waves.
There are two possible, competing ways in which dust can affect the Alfvén waves, which in turn could determine how energy is dumped into the corona, heating it. On one hand, the mass of the dust can act to provide extra inertia to the plasma as it rides the solar wind, allowing the plasma energy to be transported across wider distances. On the other hand, the electric charge on the dust grains can bolster the interactions between charged particles in the plasma, the Alfvén waves and the solar electromagnetic field.
The Parker Solar Probe is seen in this illustration, right in front of the sun. (Image credit: NASA/Johns Hopkins APL/Steve Gribben)
"If dust mass dominates, [Alfvén] wave energy may travel farther into the corona," said Ayaz. "If dust-charge effects dominate, the energy may be released more locally as particle heating."
The balance between these two effects can therefore control where and when energy is deposited into the corona, focusing it in areas and causing temperatures there to rise dramatically.
Future solar missions are now going to have to start taking dust into account, said Ayaz, with dedicated detectors designed to measure dust's properties close to the Sun.
"The bigger question is fascinating," said Ayaz. "Is dust simply passing through the near-Sun environment, or is it helping shape how electromagnetic energy becomes heat and solar-wind motion?"
More evidence that the interstellar comet 3I/ATLAS is much older than our solar system has come to light, along with clues that it formed on the outskirts of the protoplanetary disk belonging to its parent star long ago.
Earlier this year, researchers led by Martin Cordiner of NASA's Goddard Space Flight Center revealed that data from the James Webb Space Telescope (JWST) suggested that 3I/ATLAS is between 10 and 12 billion years old, based on the ratios of its carbon and deuterium isotopes. This would make it more than twice the age of our 4.6-billion-year-old solar system. Now, new results from the Ultraviolet and Visual Echelle Spectrograph (UVES) on the European Southern Observatory's Very Large Telescope support the JWST observations of carbon isotopes, and also introduce measurements of nitrogen isotopes that arrive at very interesting conclusions.
Isotopes are versions of atomic elements with different numbers of neutrons. For example, carbon-12 contains six protons and six neutrons, while carbon-13 contains six protons and seven neutrons. Meanwhile nitrogen-14 has seven protons and neutrons each, while nitrogen-15 has seven protons and eight neutrons.
These isotopes can form through subtly different processes, at different times and in different locations in the galaxy. The ratio of these isotopes in the gases released by comet 3I/ATLAS into its coma and tail as it neared the sun and grew warmer can therefore tell us much about its origin and history.
Consequently, interstellar objects such as 3I/ATLAS "are sort of fossils from a planetary formation process that happened very far away, but we get the chance to study from much closer," said astronomer Cyrielle Opitom of the University of Edinburgh in a statement.
Opitom led the team who got the chance to observe 3I/ATLAS with the VLT. They found that the ratio of carbon-12 to carbon-13 is higher than is found in comets in our solar system or indeed in the local interstellar medium. Carbon-13 is produced in greater abundances than carbon-12 over time, typically in red giant stars, so for there to be far more carbon-12 than carbon-13 tells us that 3I/ATLAS was born long ago before carbon-13 had a chance to build in abundance across the galaxy. This finding supports the JWST carbon isotope measurements.
Additionally Opitom's team, which was co-led by Jean Manfroid and Damien Hutsemékers of the University of Liège in Belgium, measured a ratio of nitrogen-14 to nitrogen-15 in 3I/ATLAS that is more than twice as large as the value measured in comets native to our solar system. In fact, the ratio is typical of that found on the outer edge of planet-forming discs around young stars, implying 3I/ATLAS formed a long way out from its parent star, perhaps in the equivalent of its Kuiper belt.
"Unlike comets from our solar system, this interstellar visitor carries unusually high carbon and nitrogen isotopic ratios," said team-member Aravind Krishnakumar, who is also of the University of Liège.
The results give us clues to how 3I/ATLAS found itself wandering the space lanes alone for billions of years. Models indicate that migrating giant planets can kick small bodies into interstellar space, but the location of 3I/ATLAS's birth far from that planetary action means that it is quite possible instead that it was snatched from its parent star by the gravity of a passing star and was subsequently hurled into deep space.
Unfortunately similar measurements were not possible with the other two known interstellar objects – 1I/'Oumuamua was not seen to outgas, while 2I/Borisov was too faint. However, 3I/ATLAS is a tantalizing indication that studies of more interstellar objects caught entering our solar system will be able to teach us about planet-forming conditions across both space and time in our Milky Way galaxy.
"3I/ATLAS is a really exciting opportunity to probe the composition of another planetary system, one that formed long before our Sun and solar system even existed," concluded Rosemary Dorsey, an astronomer from the University of Helsinki in Finland.
The findings were published on July 6 in the journal Nature Astronomy.
Three years before the skyscraper-size asteroid Apophis makes its very close (but safe) flyby of Earth, scientists have already begun charting exactly when and where billions of people can watch it sweep across the sky.
Speaking at an "Apophis T-3 Years" workshop held earlier this month at the University of Padua in Italy, retired cartographer Michael Zeiler and astronomer Rick Fienberg shared detailed visibility maps charting the asteroid's passage across Earth's skies.
According to their calculations, roughly 90% of the world's population — about 7.6 billion people — lives in regions where Apophis could, in principle, be seen with the naked eye on April 13, 2029. The actual viewing success will depend more on earthly considerations, however, including cloud cover and the extent of light pollution.
Known formally as 99942 Apophis, the space rock will not resemble a blazing meteor tearing through the sky. Instead, scientists say it will appear as a point-like speck of light gliding steadily across, which, at its closest approach, will appear to move by about the apparent width of the full moon every minute.
"It will definitely be noticeable," Fienberg told Space.com. "It's going to be moving more slowly than a satellite — it will cross the sky in hours, rather than minutes, and it will just be a point."
According to the new maps, the asteroid should remain visible to the naked eye for about seven hours, beginning over Australia at 11:00 a.m. EDT (15:00 UTC) and concluding over the North Atlantic at 6:00 p.m. EDT (22:00 UTC).
At 4:35 p.m. EDT (20:35 UTC), Apophis is expected to reach its greatest apparent brightness as it passes over Cameroon, offering prime viewing to an estimated 3.9 billion people across Africa, Asia, eastern South America and parts of Europe.
One moment of peak brightness for Apophis (as seen from Earth) at the moment of closest approach at 5:45 p.m. EDT (21:45 UTC). The asteroid will be at a height lower than geosynchronous satellites. (Image credit: Eclipseatlas.com)
About an hour later, at 5:45 p.m. EDT (21:45 UTC), the asteroid will make its closest approach to Earth, passing about 19,700 miles (31,600 kilometers) above the North Atlantic — well inside the orbit of Earth's geostationary satellites. The event would be visible across much of South America, the United States, Africa and parts of Europe, reaching roughly 2 billion people.
"This is the first time we've been able to predict in human history an asteroid visibly passing by the Earth," Richard Binzel, a professor of planetary sciences at the Massachusetts Institute of Technology (MIT), said during the workshop. "That's part of a shared experience."
As excitement ramps up for the once-in-a-millennium spectacle, Binzel opened the workshop with three messages: "Apophis will safely pass the Earth. Apophis will safely pass the Earth. Apophis will safely pass the Earth."
That absolute certainty is the hard-won fruit of more than two decades of increasingly precise observations. When Apophis was discovered in 2004, early calculations suggested a 1-in-37 chance of an impact in 2029, making it the most potentially hazardous asteroid known at the time. Additional observations steadily refined the asteroid's orbit, eliminating any possibility of a collision in 2029 and also ruling out any impact threat for at least the next century, according to NASA.
With the impact threat removed, scientists now view the flyby as a rare opportunity to observe how Earth's gravity affects an asteroid during an exceptionally close encounter.
A diagram of Earth showing where Apophis will be at the moment of closest approach on April 13, 2029. (Image credit: Eclipseatlas.com)
Our planet's gravity is expected to tug the asteroid into a new orbit around the sun without posing any future danger. During the flyby, however, those same gravitational forces may stretch and squeeze the asteroid enough to trigger landslides or expose pristine material hidden beneath its weathered surface. Or they may do almost nothing.
"We simply don't know what's going to happen," Binzel said during the workshop. "Apophis may go by and not care too much, or maybe we'll see something significant."
"That's why we have to look," he added. "We're gonna learn a lot either way."
At the workshop, scientists said they hope to monitor the flyby from observatories in Spain's Canary Islands, among other places, as its location in the Atlantic Ocean offers an ideal view of the asteroid's closest approach as well as favorable prospects for clear skies.
Humanity has likely dreamed of flight since the very beginning, marveling at birds soaring overhead and trying to puzzle out their seemingly magical secret.
We made some halting steps over the centuries — getting kites aloft in ancient China, for example, and drawing up ambitious but unrealized flying machines during the Renaissance — but our boots were still firmly rooted on the ground when the United States of America was born on July 4, 1776.
Things changed just a few years later, however. In November 1783, a hot-air balloon designed by the Montgolfier brothers carried two men on a 25-minute flight over Paris, beginning our species' exploration of the heavens.
Another 120 years passed before we managed to fly with a powered, heavier-than-air craft, a milestone notched by the Wright brothers in North Carolina on Dec. 17, 1903. Remarkably, it took us less than half that long to make the jump from the sky to the final frontier, which cosmonaut Yuri Gagarin did for the first time on April 12, 1961.
Eight years later, Apollo 11 astronauts Neil Armstrong and Buzz Aldrin walked on the moon — a remarkable achievement that was the climactic moment of the Cold War space race between the United States and the Soviet Union.
Over the next three and a half years, five more Apollo missions landed on Earth's nearest neighbor, leaving behind flags, footprints and defunct machinery. Now, more than half a century later, our species is gearing up to go back — but this time, in a much different way.
NASA wants to build a base near the moon's south pole over the next decade or so, an ambitious project the agency is undertaking via its Artemis program. And this is not an end in itself; NASA believes the knowledge gained from establishing such an outpost will help humanity make the next giant leap — to Mars.
The ball is rolling on Artemis, with two successful missions already in the books. Artemis I launched an uncrewed Orion capsule to lunar orbit and back in late 2022, and Artemis II sent four astronauts on a loop around the moon this past April. Next up is Artemis III, which will test docking procedures with one or both of the Artemis program's lunar landers (SpaceX's Starship and Blue Origin's Blue Moon) in Earth orbit in 2027. If all goes well with that flight, Artemis IV will put astronauts down near the lunar south pole, possibly as soon as 2028. (That timeline is far from guaranteed, however, as much development work remains. For example, neither Starship nor Blue Moon has yet reached Earth orbit or been cleared to carry humans.)
This is all happening in the context of a new space race, this time with China. The nation plans to land astronauts on the moon by 2030 and has been ticking boxes that keep this timeline within reach. And China aims to build a base of its own — also near the moon's south pole, which is thought to be rich in water ice — in collaboration with Russia and other partners.
What does all of this mean for the United States? Well, the nation came of age industrially after the Wright brothers' historic flight and has been a leader in aerospace tech and exploration ever since. The U.S. can accomplish amazing things in the final frontier, especially when pushed by a rival, so the years just after its 250th birthday may be quite eventful indeed. Stay tuned!
