Astro Blog

By Dennis Normile , Science.  Excerpt: Following its successes retrieving lunar samples from both the near and far sides of the Moon, China is planning an encore, sending a probe to snatch material from a near-Earth asteroid. The target of the Tianwen-2 mission, which is expected to launch by the end of the month, is a chunk of rock named 469219 Kamo‘oalewa. It is one of just seven asteroids that fall into a little-understood class known as quasi-satellites of Earth—and it could also be the first known asteroid comprised of lunar material. That hypothesis could be confirmed by laboratory studies of fragments collected by Tianwen-2, which are due to be returned to Earth about 2.5 years after launch. ...Kamo‘oalewa was discovered in 2016 by the Pan-STARRS 1 asteroid survey telescope on Haleakalā in Hawaii. It ... has been in its current orbit for about 100 years  and will likely remain there for another 300.... University of Arizona planetary scientist Benjamin Sharkey and colle...

By Molly Herring , Eos/AGU.  Excerpt: Researchers have found salts in samples from asteroid Ryugu. Combined with similar salty discoveries from asteroid Bennu, the finding suggests that aqueous incubators of life’s first ingredients may have been relatively common in the early solar system. ...The results from  Ryugu  were reported in  Nature Astronomy  in November 2024, and those from  Bennu  were reported in January 2025. The parallel discoveries paint a compelling picture of the early solar system. ...“We can now say, for the first time, that 4.5 billion years ago—long before most of us thought it could happen—we had both the ingredients and the environment in which the early stages of organic evolution towards life could begin,” said  Tim McCoy , a curator of meteorites at the Smithsonian’s National Museum of Natural History who studied the Bennu samples. Such evolution “didn’t happen on a large, icy moon or a large, warm planet like Earth. It...

By Lan Dai  and  Axel Timmermann , ScienceAdvances.  Abstract summary: Asteroid Bennu has a 0.037% chance of colliding with Earth in 2182 CE.  The potential collision of such medium-sized asteroids would inject dust into the atmosphere and disrupting climate, vegetation, and marine productivity. Simulations show global temperature drop of 4°C, reduced precipitation, and significant decreases in terrestrial and marine net primary productivity....  Full article at https://www.science.org/doi/10.1126/sciadv.adq5399 .  See also Life’s Building Blocks Found in Bennu Samples (Eos/AGU)

By Center for NEO Studies (CNEOS), JPL/CalTech.  Excerpt: CNEOS analysis of near-Earth asteroid 2024 YR4, which is estimated to be about 40 to 90 meters wide, indicates it has a more than 1% chance of impacting Earth on Dec. 22, 2032 — which also means there is almost a 99% chance this asteroid will not impact. These analyses will change from day to day as more observations are gathered. The CNEOS analyses are used for NASA’s contribution to the  International Asteroid Warning Network (IAWN) . After the impact probability for this asteroid reached 1%, IAWN issued its official  notification  for the potential impact....  Full article at https://cneos.jpl.nasa.gov/news/news210.html .  See also: International Asteroid Warning Network - https://iawn.net/obscamp/2024YR4/index.shtml , explanation of the Torino Scale on Wikipedia - https://en.wikipedia.org/wiki/Torino_scale , European Space Agency Near-Earth Objects Coordination Center - https://neo.ssa.esa.int/-...

By Daniel P. Glavin et al, Nature Astronomy.  Abstract Excerpt: Organic matter in meteorites reveals clues about early Solar System chemistry and the origin of molecules important to life.... Samples returned from the B-type asteroid Bennu by the Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer mission ...show that Bennu samples are volatile rich, with more carbon, nitrogen and ammonia than samples from asteroid Ryugu and most meteorites. ...Bennu’s parent asteroid developed in or accreted ices from a reservoir in the outer Solar System where ammonia ice was stable. ...The transport and delivery of organic compounds from these bodies could have been a source of molecules available for the emergence of life on Earth and potentially elsewhere....  Full article at https://www.nature.com/articles/s41550-024-02472-9 .  See also Nature article An evaporite sequence from ancient brine recorded in Bennu samples [Brines ...are environment...

By Mark Zastrow , Astronomy.  Excerpt: On Jan. 2, the Minor Planet Center at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, announced the  discovery of an unusual asteroid , designated 2018 CN41. First identified and submitted by a citizen scientist, the object’s orbit ...came less than 150,000 miles (240,000 km) from Earth, closer than the orbit of the Moon. That qualified it as a near-Earth object (NEO) — one worth monitoring for its potential to someday slam into Earth. But less than 17 hours later, the Minor Planet Center (MPC) issued an  editorial notice : It was deleting 2018 CN41 from its records because, it turned out, the object was not an asteroid. It was a car. To be precise, it was  Elon Musk’s Tesla Roadster  mounted to a Falcon Heavy upper stage, which boosted into orbit around the Sun on Feb. 6, 2018....  Full article at https://www.astronomy.com/science/astronomers-just-deleted-an-asteroid-because-it-turned-out-...

By Douglas Fox , SciAm.  Excerpt: Sixty-six million years ago a 10-kilometer-wide space rock fell out of the sky over what is now the Yucatán Peninsula in the Gulf of Mexico. ...Yet the event’s infamous impactor was nothing compared with the asteroid that struck Earth 3.26 billion years ago, amid what scientists call the Archean eon of our planet’s 4.5-billion-year history. The Archean space rock in that impact, dubbed “S2,” was 50 to 200 times larger—big enough to blast at least 10,000 cubic kilometers of vaporized rock into the skies that then recondensed into molten droplets and rained back to Earth. Unsurprisingly, those circumstances would have been “really disastrous for early life,” says Nadja Drabon, a geologist at Harvard University. But her latest research suggests that—much like the more celebrated dino-killing space-rock impact—this vastly greater and more ancient collision also had an upside, giving Earth’s early biosphere a powerful boost. ...her scrutiny of rock laye...

By Jonathan O'Callaghan , Nature.  Excerpt: Experiment shows that, in a worst-case scenario, humanity could use a nuclear explosion to save the planet from a deadly impact. A blast of X-rays from a nuclear explosion should be enough to save Earth from an incoming asteroid, according to the results of a first-of-its-kind experiment. The findings, published 1  on 23 September in  Nature Physics [ https://www.nature.com/articles/s41567-024-02633-7 ], “showed some really amazing direct experimental evidence for how effective this technique can be”, says Dawn Graninger, a physicist at Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland. “It’s very impressive work.”  Full article at https://www.nature.com/articles/d41586-024-03128-4 . 

By Rebecca Schneid , Time.  Excerpt: Starting next week, the moon, Earth’s closest celestial body, will be joined by a new neighbor: a second moon. From Sept. 29 until Nov. 25, astronomers calculate that 2024 PT5— which is what scientists think is an asteroid but have dubbed a “mini-moon”—will be looping around Earth. It will eventually break free of the planet’s gravitational orbit. Sadly, at just about 10 meters, the mini-moon will be extremely hard to see from Earth, but its presence will be there nonetheless for almost two months. The asteroid, which was discovered on Aug. 7 by  NASA , originated from the Arjuna asteroid belt, where it will likely return once it leaves Earth’s orbit. “Earth can regularly capture asteroids from the Near-Earth object (NEO) population and pull them into orbit, making them mini-moons,” researchers Carlos de la Fuente Marcos and Raúl de la Fuente Marcos wrote in their  published research ....  Full article at https://time.com/7022535/...

By DANIEL CLERY , Science.  Excerpt: Astronomers suspect an unusual near-Earth rocky object is not a typical escapee from the Solar System’s asteroid belt, but is instead a chunk of the Moon blasted into space eons ago by a spectacular impact. Now, a team of researchers has modeled what sort of lunar impact could have ejected such a gobbet of Moon and deposit it in a stable, nearby orbit. Surprisingly, only one strong candidate emerged: the asteroid strike that created the famous Giordano Bruno crater, the youngest large crater on the Moon, the  group reports today  in Nature Astronomy. ...The odd asteroid, known as 469219 Kamo‘oalewa, was discovered in 2016 ...measures between 40 and 100 meters across and rotates particularly fast—once every 28 minutes. It follows an elliptical orbit around the Sun that moves in sync with Earth, giving the impression that the asteroid orbits Earth, even though it is outside the planet’s gravitational influence. The asteroid’s curiou...

https://skyandtelescope.org/astronomy-news/lucy-mission-flies-by-asteroid-dinkinesh-finds-a-little-surprise By EMILY LAKDAWALLA , Sky & Telescope. Excerpt: On November 1st, the Lucy mission zipped past the tiny asteroid 152830 Dinkinesh and discovered that it was actually a binary. ...While the probe caught a view of the Dinkinesh's small satellite in the one of the first images of the flyby, the mission turned as it flew by and captured another view from a different angle. That new perspective revealed that the little asteroidal moon is actually a  contact binary , meaning it's made of two objects in contact with one another. This is the first contact binary asteroid moon discovered. Read more details on  NASA's website ....

https://www.science.org/content/article/nasa-delivers-bounty-asteroid-samples-earth By PAUL VOOSEN , Science.  Excerpt: ...today, after detaching from NASA’s OSIRIS-REx spacecraft, a capsule carrying asteroid samples descended gently by parachute before touching down in the Utah desert. The cupful of pebbles and grit it delivered—the culmination of 7 years of effort and $1 billion of expense—is only the third sample of an asteroid ever returned to Earth, and it’s the largest haul of extraterrestrial material NASA has collected since the Apollo Moon missions. ...In 2020, Japan’s Hayabusa2 spacecraft returned some 5 grams of material from Ryugu, another carbon-rich, near-Earth asteroid, which was thought to be relatively dry. Instead, it appears to have been fully altered by water. “We were all terribly wrong about Ryugu,” says Edward Young, a cosmochemist at the University of California, Los Angeles. ...If they are wrong about Bennu, it will be the opposite mistake. Remote observati...

https://www.nytimes.com/2023/09/15/science/jupiter-comet-flashes.html By Katrina Miller , The New York Times.  Excerpt: Ko Arimatsu, an astronomer at Kyoto University in Japan, received an intriguing email... An amateur astronomer in his country had spotted a bright flash in Jupiter’s atmosphere. Dr. Arimatsu, who runs an  observation program  to study the outer solar system using backyard astronomy equipment, put out a call for more information. Six more reports of the Aug. 28 flash — which, according to Dr. Arimatsu, is one of the brightest ever recorded on the giant gas planet — came in from Japanese skywatchers. Flashes like these are caused by asteroids or comets from the edges of our solar system that impact Jupiter’s atmosphere. “Direct observation of these bodies is virtually impossible, ...,” Dr. Arimatsu wrote.... But Jupiter’s gravity lures in these objects, which eventually slam into the planet, “making it a unique and invaluable tool for studying them directl...

https://skyandtelescope.org/astronomy-news/does-earth-have-new-quasi-moon/ By David Chandler, Sky & Telescope Magazine.  Excerpt: Recently discovered asteroid 2023 FW 13  has created a bit of a stir among asteroid watchers. It turns out to be on an orbit that is not only in a 1:1 resonance with the Earth, but follows a path that actually circles Earth — albeit on an orbit that is so eccentric that it sweeps out halfway to Mars and in halfway to Venus. There’s no formal definition for objects such as this, which are sometimes called quasi-moons or quasi-satellites. They follow a path around Earth, but usually for no more than a few decades. Perhaps the best known of these objects, known as Kamoʻoalewa, was  found in 2016 , and is considered the smallest, closest, and most stable known quasi-satellite. It has an orbit that has been in a stable resonance with Earth for almost a century, and will remain so for centuries to come, according to calculations by Paul Chodas (J...

https://www.science.org/content/article/earth-higher-risk-big-asteroid-strike-satellite-data-suggest By Paul Voosen, Science.  Excerpt: At a basic level, humanity’s survival odds come down to one thing: the chances of a giant space rock slamming into the planet and sending us the way of the dinosaurs. One way to calibrate that hazard is to look at the size of Earth’s recent large impact craters. And a provocative new study suggests they are bigger than previously thought—meaning Earth is more at risk of getting hit hard, says James Garvin, chief scientist of NASA’s Goddard Space Flight Center,  who presented the work  last week at the Lunar and Planetary Science Conference. ...Using a new catalog of high-resolution satellite imagery, Garvin and his colleagues identified large rings around three impact craters and one probable one that are 1 million years old or younger. To Garvin, the rings imply the craters are tens of kilometers wider, and record far more violent events...

https://www.nytimes.com/2023/02/08/science/quaoar-rings-roche-limit.html By Kenneth Chang , The New York Times.  Excerpt: Quaoar, which orbits the sun in the distant Kuiper belt, is the latest small object shown to have a ring like the ones around Saturn. ...Quaoar (pronounced KWA-wahr ...is a little less than half the diameter of Pluto and about a third of the diameter of Earth’s moon. It is likely to be big enough to  qualify as a dwarf planet , pulled by its gravity into a round shape. ...The ring is not visible in telescope images. Rather, astronomers found it indirectly, when distant stars happened to pass behind Quaoar, blocking the starlight. From 2018 through 2021, Quaoar passed in front of four stars, and astronomers on Earth were able to observe the shadow of the eclipses, also known as stellar occultations. However, they also observed some dimming of the starlight before and after the star blinked out. That pointed to a ring obscuring part of the light, an inte...

https://skyandtelescope.org/astronomy-blogs/space-missions-to-watch-in-2023/ By Sky & Telescope.  Excerpts: ...SpaceX’s Starship ...Axiom Space’s AX2 ... to the International Space Station ...ESA’s  Euclid  space telescope ...an infrared instrument, aimed at studying dark matter and dark energy ...Indian Space Research Organization (ISRO) ...X-ray Polarimeter Satellite, ...and the Aditya L1 solar mission, headed to the Earth-Sun L 1  point. ...China’s  Xuntian Space Telescope , a sky survey telescope ...China also plans to launch two X-ray telescopes in 2023 ...The Moon will be bustling in 2023. Three missions [to the Moon] are at least partially NASA-funded through its  Commercial Lunar Payload Services . ...The  Polar Resources Ice Mining Experiment  (PRIME 1) is set to launch in June, carrying with it The Regolith and Ice Drill for Exploring New Terrain. The TRIDENT drill will delve three feet deep to bring lunar regolith up to th...

https://www.theguardian.com/science/2022/nov/16/meteorite-that-landed-in-cotswolds-may-solve-mystery-of-earths-water By  Hannah Devlin , The Guardian.  Excerpt: Water covers three-quarters of the Earth’s surface and was crucial for the emergence of life, but its origins have remained a subject of active debate among scientists. Now, a 4.6bn-year-old rock that crashed on to a  driveway in Gloucestershire last year  has provided some of the most compelling evidence to date that water arrived on Earth from asteroids in the outer solar system.... 

https://www.nytimes.com/2022/10/31/science/asteroid-planet-killer.html By Robin George Andrews , The New York Times.  Excerpt: Last year, in the hope of finding asteroids cloaked by excessive sunlight, an international team of astronomers co-opted a camera primarily designed to investigate the universe’s notoriously elusive dark energy. In  an announcement Monday  based on a survey first published in September in  The Astronomical Journal , the researchers announced the discovery of three new light-drowned projectiles. One of them, 2022 AP7, is roughly a mile long, and its orbit crosses Earth’s path around the sun, getting as near as 4.4 million miles to Earth itself — uncomfortably close by cosmic standards (although far more distant than Earth’s moon). That makes 2022 AP7 “the largest potentially hazardous asteroid found in the last eight years or so,” said  Scott Sheppard , an astronomer at the Carnegie Institution for Science in Washington, D.C., and an auth...

https://www.nasa.gov/press-release/nasa-confirms-dart-mission-impact-changed-asteroid-s-motion-in-space By NASA  RELEASE 22-105 .  Excerpt:  Analysis of data obtained over the past two weeks  by NASA’s Double Asteroid Redirection Test (DART) investigation team shows the spacecraft's kinetic impact with its target asteroid, Dimorphos, successfully altered the asteroid’s orbit. This marks humanity’s first time purposely changing the motion of a celestial object and the first full-scale demonstration of asteroid deflection technology. “All of us have a responsibility to protect our home planet. After all, it’s the only one we have,” said NASA Administrator Bill Nelson. “This mission shows that NASA is trying to be ready for whatever the universe throws at us. NASA has proven we are serious as a defender of the planet. This is a watershed moment for planetary defense and all of humanity, demonstrating commitment from NASA's exceptional team and partners from around ...