China’s Tianwen-1 orbiter caught a rare glimpse of 3I/ATLAS as it swept past Mars, revealing the hazy coma and tail of a comet born beyond our solar system. The interstellar object known as 3I/ATLAS just flew past Mars, and China’s Tianwen-1 mission managed to snap some pics with its high-resolution camera. According to the China [...]
Last summer, astronomers were observing the near approach of a space object believed to be an asteroid that had been tracked since its discovery in 1998. However, in a surprising development, the object failed to appear where it was predicted to be after decades of observations.
Now, a team of researchers reports in a new study that this mysterious orbital body is no asteroid at all, but instead may be an elusive class of space objects that scientists are still working to fully understand.
The research, published in the journal Nature Astronomy, identifies the newly suspected reasons for this unexpected “dark” twist in the developing story of 1998 SH2, a celestial body once thought to be a common space rock that is now upending past thinking on how to protect Earth from potential impact risks.
Since its discovery in 1998, the object designated 1998 SH2 has been monitored by astronomers continuously, providing close to three decades of observations that inform us about its orbit, leaving what researchers thought would be little room for surprises.
That all changed last August as the anticipated return of 1998 SH2 approached. Based on radar observations, the object appeared to be absent from its expected orbital path—a mystery that initially baffled astronomers.
Eventually, once the near-Earth object was spotted again by Brazil’s Southern Observatory for Near Earth Asteroids Research, it had moved significantly beyond its expected path. But what could account for such an unusual display?
Now, according to Jet Propulsion Lab and CalTech researcher Davide Farnocchia and colleagues, 1998 SH2 was likely steered off course as a result of jets of gas escaping from beneath the object’s surface—a phenomenon known as weak cometary outgassing—meaning that the suspected asteroid is actually probably a type of comet.
However, unlike most comets, this one showed none of the typical characteristics astronomers associate with them, including a glowing tail or coma. This helped to explain the confusion over its initial classification, and additional observations of layered composite imagery did finally reveal these features, albeit faintly.
This confirmation that the object was indeed releasing material meant that 1998 SH2 was a rare variety of space objects known as dark comets, enigmatic bodies whose subtle behavior falls somewhere between comets and asteroids.
One of the more concerning aspects of the discovery involves 1998 SH2’s unexpected orbital shift, which presents the question of whether other suspected asteroids might turn out to be dark comets. If so, could any of these shifty space objects pose a risk to Earth?
Fortunately, Farnocchia and his colleagues say there is currently no indication that 1998 SH2 poses an impact threat to Earth in the foreseeable future. Still, the team’s findings do have important implications for planetary defense, since their findings underscore the possibility that additional near-Earth objects currently classified as asteroids may turn out to be hidden comets.
Given the unpredictable orbital shifts and changes in acceleration these objects display, challenges associated with identifying and tracking them could complicate long-term impact forecasts, and influence how future deflection missions are designed.
Fortunately, the team’s study also highlights beneficial findings, which include the possibility that a hidden population of dark comets could potentially resolve questions about how water was delivered throughout the early solar system, eventually making its way to a young planet Earth billions of years ago.
Additionally, such possibilities could help to explain past observations of enigmatic objects like ‘Oumuamua, the first confirmed interstellar object, whose detection in 2017 and unexplained acceleration during subsequent observations have fueled scientific debate over its origins for many years.
Farnocchia and his colleagues’ new paper, “Non-gravitational acceleration indicative of cometary activity of near-Earth object,” appeared in Nature Astronomy.
Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. A longtime reporter on science, defense, and technology with a focus on space and astronomy, he can be reached at micah@thedebrief.org. Follow him on X @MicahHanks, and at micahhanks.com.
When you think of an asteroid impact, you’re probably imagining something like the cataclysmic event that nearly wiped out the dinosaurs. In an astonishingly rare event, a rock the size of the island of Manhattan could come hurtling from deep space towards Earth and destroy the world.
On the contrary, asteroids are generally leftover debris from the primordial solar system that didn’t become part of a larger body, like a planet or moon, and they’re not particularly rare. Scientists estimate that there are about 1 billion asteroids and comets classified as near-Earth objects, or NEOs. NEOs are generally much smaller than the asteroid that killed the dinosaurs. They range from weakly held-together piles of rubble 200 meters (700 feet) across, to the minuscule 2024 BX1, approximately 44 centimeters (17 inches) across.
For several decades, astronomical surveys of the sky have looked for these asteroids. NASA’s Center for Near-Earth Object Studies (CNEOS) Fireball and Bolide Database has records of over 1,000 incidents of objects colliding with our planet since the mid-1990s. Among these is a set of 11 objects that scientists detected before they hit Earth, known as imminent impactors. Finding imminent impactors allows scientists unique opportunities to study the smallest building blocks of the solar system, enabling them to learn more about asteroid composition, structure, and history.
A team of scientists recently conducted a study on how the newly built Vera Rubin Observatory could detect more imminent impactors before they strike Earth. They examined the CNEOS Fireball and Bolide Database impact records spanning February 1, 1994, to January 1, 2026, for records of the asteroids’ coordinates, velocities, and the energy they released at the time of collision.
They found that 343 NEOs met this criterion, including 5 known imminent impactors. Using these recorded data, they reconstructed the objects’ pre-impact characteristics. The team predicted the asteroids’ orbital paths from the recorded coordinates and velocity. Assuming the objects were spherical, they estimated the size from velocity and impact energy. From this information about the asteroids’ state before impact, the team could then simulate whether the Rubin Observatory would have detected them.
When small asteroids hit Earth, they mostly burn up in the atmosphere, producing a bright flash that is relatively easy to spot compared to when they are in space. The Rubin Observatory can see objects up to 10 billion times dimmer than the brightest star in the night sky, Sirius. To predict if the Rubin Observatory can detect dim NEOs, the team used the solar system simulator SORCHA. SORCHA takes an observatory’s specifications and the physical properties of the NEOs and uses these to determine whether the observatory could detect them. It also estimates the measured sizes and speeds of the NEOs, and predicts when the observatory would have seen them.
At the Rubin Observatory, an imminent impactor is considered discovered if it’s observed at least 3 separate times over 15 days before hitting Earth. So this team applied this same criterion to their simulation. They found that of their 343 impactors, SORCHA estimated that the Rubin Observatory would have discovered 14 of them before impact.
They also found that SORCHA predicted 4 additional impactors that could have been observed at least once, potentially allowing scientists to search other telescope data for evidence of their existence in pre-collision images. Based on these results, the team estimated that the Rubin Observatory could find 4% of all objects longer than 1 meter (3 feet) before they hit Earth. This percentage of discovery translates to 1 to 2 imminent impactors detected every year, at least double their current discovery rate.
The ability to more consistently find imminent impactors would allow researchers to study the smallest pieces of the solar system in detail and to draw general conclusions about the properties of objects that could potentially collide with Earth. This would also allow scientists to more accurately calculate the orbits of imminent impactors, determine where more meteorites land to recover them, and keep tabs on the extremely rare but more hazardous large impactors for planetary defense initiatives. So, humanity can learn more about the ancient solar system, and hopefully avoid going the way of the dinosaurs while doing so!
The post How many asteroids can we detect before they hit Earth? appeared first on Sciworthy.
Astronomers have found that interstellar comet 3I/ATLAS contains an unusually large amount of methanol. Every interstellar object that passes through our solar system offers a rare chance to sample material forged around another star. Now, new observations of comet 3I/ATLAS using the Atacama Large Millimeter/submillimeter Array (ALMA) have revealed a chemical surprise: the comet is [...]A process called ‘hot bottom burning’ helped scientists determine the age of 3I/ATLAS.
The interstellar comet 3I/ATLAS carries a chemical fingerprint unlike anything in our Solar System, and it may have formed 10 to 12 billion years ago, before our Sun even existed, according to two papers published in the journal Nature.
The post Interstellar Comet 3I/ATLAS Formed Up To 12 Billion Years Ago, New Observations Suggest appeared first on Sci.News: Breaking Science News.
He also strapped wings to his hands and feet and glided for 200 meters.Early in the 11th century, a young Benedictine monk named Eilmer jumped from the 150-foot tower of his abbey in the small English town of Malmesbury, wearing a pair of crude wings he’d fashioned from willow wood and cloth. Eilmer managed to glide a good 600 feet, passing over the city wall before crash-landing in a small valley near the river Avon. The fall broke both his legs, crippling him. Malmesbury Abbey still boasts a stained-glass window in honor of Brother Eilmer.
This legendary experiment in medieval aviation comes to us via 12th-century historian William of Malmesbury in an account written circa 1125, although William neglected to provide future historians with an exact date for the feat. But William does mention another key episode in Eilmer's life when the monk was "advanced in years": Eilmer witnessed Halley's comet in 1066, commenting, "It is long since I saw you." Some historians have interpreted this to mean that Eilmer saw Halley's comet on an earlier fly-by in 989, when he would have been a young boy.
Assuming Eilmer was at least 5 years old in 989, he would have been born no later than 984. This would make Eilmer in his 80s in 1066, with his attempt at flight—which occurred when he was "in his first youth"—likely falling between 1000 and 1010. However, it's an estimate that is based on a lot of assumptions, according to James Aitcheson of the University of Leicester, who argues in a paper published in the journal Notes and Queries that Eilmer may have seen a different comet altogether in his youth—the comet of 1018. If so, he would have been born much later, and the date of his flight would have occurred between the 1020s and 1040s.
© Andrew Dunn/CC BY-SA 2.0
Using the SETI Institute’s Allen Telescope Array, a 42-element radio interferometer at Hat Creek Radio Observatory in Hat Creek, California, astronomers probed 3I/ATLAS for artificial radio transmissions but found only human-made interference.
The post Astronomers Scan Interstellar Object 3I/ATLAS for Alien Radio Signals appeared first on Sci.News: Breaking Science News.
Astronomers from around the world were fascinated last year when 3I/ATLAS, the third interstellar object ever observed passing through our Solar System, was discovered.
The SETI Institute was one of the many organizations that examined the unusual interstellar object, conducting a comprehensive search for any signs that it might be producing technological signals.
Using the Allen Telescope Array (ATA) at the Hat Creek Radio Observatory in Northern California, SETI researchers scanned a broad range of radio frequencies in search of potential evidence of extraterrestrial technology associated with 3I/ATLAS. The data that came back was clear: no signs of artificial signals. As most astronomers expected, 3I/ATLAS is most likely a natural comet.
Observations of interstellar objects have become more common in recent years, due to advances in telescopic technologies available to astronomers. Discovered last July, 3I/ATLAS is only the third confirmed interstellar visitor to enter our Solar System, preceded by 1I/ʻOumuamua in 2017, and 2I/Borisov in 2019.
These rare discoveries help astronomers understand the materials in our cosmic backyard. By analyzing the composition of these objects, scientists can gain a deeper understanding of how planetary systems develop and evolve throughout the galaxy.
The majority of recent astronomical observations indicate that 3I/ATLAS is a natural object, albeit one that exhibited some unusual qualities. However, the possibility remains that we may one day find a technological artifact from an intelligent civilization; it is equally possible that at some point, aliens may also discover a spacecraft of Earthly origin.
“Eventually, our own Voyager spacecraft will be extraterrestrial artifacts in other stellar systems,” Sheik told The Debrief. “Given that, it is important that we understand the natural distribution of interstellar objects so that we will be able to identify any anomalies that could one day be signs of an artificial interstellar object.”
The SETI research team studied 3I/ATLAS for over seven hours using the ATA, searching radio frequencies from 1 to 9 gigahertz. This range is especially important because it can detect narrowband radio signals, which are rarely produced by natural space phenomena and are often considered possible signs of technological activity.
Researchers found 74 million narrowband signals, but after filtering out human interference and motion-matched sources, only about 200 remained. These were later confirmed to come entirely from Earth-based technology or satellites.
“To be clear, we did not detect any radio signals from 3I/ATLAS. We ruled out the presence of signals down to power levels comparable with everyday appliances: for example, we definitely would have picked up a cell tower or a radio station equivalent had it been on the surface of 3I/ATLAS,” Sheik said.
In other words, no technosignatures were detected. The SETI observation ruled out signals stronger than approximately 10 to 110 watts across the observed frequencies (comparable to the power consumption of a household appliance).
For a time, there was a considerable amount of speculation over whether 3I/ATLAS could represent something more than just a natural object. Among the proponents of such ideas, theoretical physicist Avi Loeb emerged as one of the most visible supporters of the possibility that the interstellar object displayed anomalous qualities that could point to technological origins.
Last July, shortly after the object’s discovery, Loeb predicted on his Medium page that 3I/ATLAS may be one of two things: a comet possessing a smaller core with a radius less than 400 meters, or “an object that favored a radial orbit into the inner solar system,” meaning that it may also be a larger object compared to its predecessors. Indeed, further observations of the object eventually suggested that 3I/ATLAS appears to be significantly larger than ‘Oumuamua or Borisov was.
Loeb also suggested in a podcast interview that 3I/ATLAS might not be following a random trajectory, but rather that its current motion could be understood as “directed” toward the inner solar system.
“That obviously opens the door for it being technological, because who would target the inner solar system?” said Loeb during an interview.
In an email to The Debrief, Loeb shared his thoughts on the recent SETI findings.
“Radio communication is an old technology, which was recently accompanied by optical laser communication in NASA’s Artemis II mission to the Moon,” Loeb said. “Lasers might replace radio communication in our future space missions, and there is no guarantee that they would operate at the frequencies scanned in this study.”
“To save power, a technological transmitter might beam its signal in the direction of the receiver (rather than Earth) and might only transmit sporadically,” Loeb added.
Last September, Loeb also looked at another fairly remote possibility: that the famous “Wow!” signal might be somehow related to 3I/ATLAS.
“Interestingly, the anomalous ‘Wow! Signal’ detected on August 15, 1977, came from a direction which is separated by only 9 degrees from the arrival direction of 3I/ATLAS into the inner Solar System, but a similar signal was never detected again,” Loeb told The Debrief.
For Sheik and the team, while 3I/ATLAS did not display any obvious signatures that could be associated with technosignatures, it still provided a significant learning opportunity.
“The results from 3I/ATLAS show how realistic it is to detect a signal with the technology we have today,” said co-author Valeria Garcia Lopez. “That is why it is important to keep searching for technosignatures, even from objects we might not expect to have signals.”
Additionally, this project highlighted the ATA’s ability to respond quickly to new discoveries. Observations began less than 24 hours after the discovery of 3I/ATLAS was announced, showcasing the telescope’s flexibility and preparedness.
Chrissy Newton is a PR professional and the founder of VOCAB Communications. She currently appears on The Discovery Channel and Max and hosts the Rebelliously Curious podcast, which can be found on YouTube and on all audio podcast streaming platforms. Follow her on X: @ChrissyNewton, Instagram: @BeingChrissyNewton, and chrissynewton.com. To contact Chrissy with a story, please email chrissy @ thedebrief.org.
An interstellar comet just revealed hidden methane and chemical clues from another star system. NASA’s James Webb Space Telescope has achieved another milestone by capturing the first mid-infrared chemical fingerprint of an interstellar object. The observations focused on comet 3I/ATLAS, a rare visitor from beyond our solar system, and the findings have been published in [...]Using the spectral data from the Mid-Infrared Instrument (MIRI) onboard the NASA/ESA/CSA James Webb Space Telescope, astronomers have detected methane on 3I/ATLAS.
The post Webb Detects Methane on Interstellar Comet 3I/ATLAS appeared first on Sci.News: Breaking Science News.
Although Halley’s Comet will not return to our vicinity for another 35 years, a new analysis has sparked media attention with the claim that this famous object is wrongly named. Professors Michael Lewis of the British Museum and Simon Zwart of Leiden University have presented evidence that the monk Eilmer of Malmesbury recognized the comet’s […]
The post Should Halley’s Comet Be Renamed? appeared first on Curiosmos.
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