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- The Gaia mission\u2019s 3rd data release<\/strong> has revealed the precise orbits of more than 150,000 asteroids.<\/li>\n
- Among these, hundreds of asteroids<\/strong> showed a wobble in their orbit that could indicate a possible moon.<\/li>\n
- If the moons are confirmed<\/strong>, it would nearly double the number of known binary asteroids.<\/li>\n<\/ul>\n
ESA published this original article on August 8, 2024. Edits by EarthSky.<\/p>\n
Gaia spots hundreds of asteroids with possible moons<\/h3>\n
ESA\u2019s star-surveying Gaia mission has again proven to be a formidable asteroid explorer. It has spotted potential moons around more than 350 asteroids not known to have a companion. Previously, Gaia had explored asteroids known to have moons \u2013 so-called binary asteroids \u2013 and confirmed that the telltale signs of these tiny moons show up in the telescope\u2019s ultra-accurate astrometric data. But this new finding proves that Gaia can conduct \u201cblind\u201d searches to discover completely new candidates, too.<\/p>\n
Luana Liberato of Observatoire de la C\u00f4te d\u2019Azur, France, is the lead author of the new study. Liberato said: <\/p>\n
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Binary asteroids are difficult to find as they are mostly so small and far away from us. Despite us expecting just under 1\/6 of asteroids to have a companion, so far we have only found 500 of the millions of known asteroids to be in binary systems. But this discovery shows that there are many asteroid moons out there just waiting to be found.<\/p>\n<\/blockquote>\n
If confirmed, this new finding adds 352 more binary candidates to the tally, nearly doubling the known number of asteroids with moons.<\/p>\n
![\"Art](\"https:\/\/earthsky.org\/upl\/2024\/08\/Gaia_spots_possible_moons_around_hundreds_of_asteroids-scaled-e1723131071509.jpg\")
View larger. | Gaia has spotted potential moons around more than 350 asteroids not known to have a companion. This new finding proves the mission can conduct \u201cblind\u201d searches to discover completely new candidates. If confirmed, this new finding adds 352 more binary candidates to the tally, nearly doubling the known number of asteroids with moons. Image via ESA\/ CC BY-SA 3.0 IGO.<\/figcaption><\/figure>\n Asteroid discoveries<\/h3>\n
Asteroids are fascinating objects. And they hold unique insights into the formation and evolution of the solar system. Binaries are even more exciting, enabling us to study how different bodies form, collide and interact in space.<\/p>\n
Thanks to its unique all-sky scanning capabilities, Gaia has made a number of important asteroid discoveries since its launch in 2013.<\/p>\n
In its data release 3, Gaia precisely pinpointed the positions and motions of 150,000-plus asteroids. In fact, its observations are so precise that scientists could dig deeper and hunt for asteroids displaying the characteristic \u201cwobble\u201d caused by the tug of an orbiting companion. (It\u2019s the same mechanism as displayed here for a binary star.) Gaia also gathered data on asteroid chemistry, compiling the largest ever collection of asteroid reflectance spectra (light curves that reveal an object\u2019s color and composition).<\/p>\n
The 150,000-plus orbits determined in Gaia\u2019s data release 3 were refined and made 20 times more precise. This advancement was part of the mission\u2019s Focused Product Release last year. Astronomers anticipate even more asteroid orbits as part of Gaia\u2019s forthcoming data release 4 (expected not before mid-2026).<\/p>\n
Timo Prusti, Project Scientist for Gaia at ESA, said: <\/p>\n
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Gaia has proven to be an outstanding asteroid explorer and is hard at work revealing the secrets of the cosmos both within and beyond the solar system. This finding highlights how each Gaia data release is a major step up in data quality and demonstrates the amazing new science made possible by the mission.<\/p>\n<\/blockquote>\n
![\"A](\"https:\/\/earthsky.org\/upl\/2024\/08\/20_times_more_precise_Gaia_maps_150_000_asteroid_orbits-scaled-e1723131529790.jpg\")
Using Gaia observations, scientists have pinpointed the positions of 156,823 asteroid orbits, making them 20 times more precise. The wider blue and yellow circles in the frame show planetary orbits, while the myriad colorful inner swirls are asteroids. The central region all lies within the orbit of Jupiter (blue circle). Image via ESA\/ Gaia\/ DPAC\/ CC BY-SA 3.0 IGO.<\/figcaption><\/figure>\n Hera mission to asteroids<\/h3>\n
ESA will further explore binary asteroids via the forthcoming Hera mission. Hera is due to launch later this year. Hera will follow up on NASA\u2019s DART mission to produce a post-impact survey of Dimorphos. DART collided with Dimorphos, a moonlet orbiting the asteroid Didymos, in 2022 as an asteroid deflection test. Hera will be the first probe to rendezvous with a binary asteroid system.<\/p>\n
Gaia helped astronomers view the shadow cast by Didymos as it passed in front of more distant stars in 2022. This is an observing technique known as stellar occultation.
Gaia\u2019s asteroid orbits and ultra-precise star maps have drastically increased the feasibility of this technique in recent years. And that proves the mission\u2019s immense value for solar system exploration.<\/p>\nBottom line: The Gaia mission\u2019s 3rd release of data has revealed precise orbits of more than 150,000 asteroids. This has allowed astronomers to look for small wobbles in the asteroids\u2019 orbits, indicating the possible presence of moons.<\/p>\n
Via ESA<\/p>\n
<\/div>\n
\n - Among these, hundreds of asteroids<\/strong> showed a wobble in their orbit that could indicate a possible moon.<\/li>\n