New evaluation displays that roughly 70% of meteorites originate from not lower than three newest break-ups of giant asteroids.
That’s an artist’s impression of an asteroid breaking up. Credit score rating: NASA / JPL-Caltech.
A class of meteorites known as atypical chondrites make up spherical 80% of meteorites which have impacted Earth, along with these involved in an intense interval of affect events roughly 466 million years prior to now that appear to have triggered an ice age.
Earlier evaluation has demonstrated that about 70% of meteorites on Earth have compositions typically generally known as H and L chondrites.
Argon-argon courting of L chondrite meteorites on Earth revealed that these samples doable originated from the catastrophic disruption of a single asteroid that expert a supersonic affect roughly 470 million years prior to now.
In a new studyDr. Michael Marsset, a researcher at ESO and MIT, and colleagues compiled spectroscopic info of asteroids within the precept belt between Mars and Jupiter.
They found {{that a}} group of asteroids typically generally known as the Massalia family is intently very similar to the composition of L chondrite meteorites on Earth.
Via laptop computer modeling, they recommend that an affect event broke up an L chondrite asteroid roughly 450 million years prior to now, forming the Massalia family and providing the particles that fuelled the meteorite influx.
In a second studyCharles School researcher Miroslav Brož and colleagues found that the current influx of H and L chondrite meteorites was doable introduced on by three newer breakups.
These events occurred about 5.8, 7.6, and 40 million years prior to now, and observed the destruction of asteroids larger than 30 km (18.6 miles) in diameter.
Further notably, they deduced that the collisional formation of the comparatively youthful Karin and Koronis asteroid households, and a second collisional event (about 40 million years prior to now) throughout the older Massalia family, make clear the overwhelming majority of the meteorites at current falling to Earth.
In a third, follow-up studyDr. Brož and co-authors extended their technique to all meteorite households, revealing the primary sources of the carbonaceous chondrites and achondrites, which come together with these from the Moon, Mars, and Vesta.
“Our findings provide insights into the mysteries surrounding the place the most common meteorites which have impacted Earth so far bought right here from and the best way these impacts may have shaped Earth’s historic previous,” they acknowledged.
The outcomes appear in three papers throughout the journal Nature and the journal Astronomy & Astrophysics.
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M. Marsset et al. 2024. The Massalia asteroid family as a result of the origin of atypical L chondrites. Nature 634, 561-565; two: 10.1038/s41586-024-08007-6
M. Brož et al. 2024. Youthful asteroid households as the primary provide of meteorites. Nature 634, 566-571; two: 10.1038/s41586-024-08006-7
M. Brož et al. 2024. Provide areas of carbonaceous meteorites and near-Earth objects. A&A 689, A183; two: 10.1051/0004-6361/202450532