Scientists Discover 70% of Meteorites That Hit Earth Come from Same Three Asteroid Families
Scientists have uncovered the origins of 90% of the known meteorites that arrive on the Earth. A team of international researchers led by experts from the CNRS, the European Southern Observatory (ESO, Europe), and Charles University (Czech Republic) made the discovery, Phys.org reported.
The researchers deduced that 70% of all identified meteorite falls originate from three young asteroid families in space. Findings regarding the discovery have been published in the journal Astronomy and Astrophysics.
Scientists have traced 70% of the earth-bound meteorites to Karin, Koronis, and Massalia families, Earth reported. The team has identified the Massalia family as the source of 37% of known meteorites. They are identified as 'young' families because the collision that led to their origination happened fairly recently, in the context of the universe.
Karin, Koronis, and Massalia families were born from collisions in the main asteroid belt that happened 5.8, 7.5, and roughly 40 million years ago. Their small lifecycle compared to other families makes them a good source of earth-bound meteorites, according to the researchers.
The lifecycle of these 'young' families causes them to contain an abundance of small fragments left over from their origin collisions. These small fragments, with their high mobility, enhance the likelihood of collisions, that could result in them being pushed out of their belt, and hurled towards the earth. The families built out of older collisions, do not face this issue because they contain "depleted" sources of meteorites. Their fragments have eroded over time, and do not contain the energy needed to escape from belts.
The discovery was facilitated with the help of a telescopic survey of the composition of all the major asteroid families in the main belt, Earth reported. On the basis of the data collected from this survey, simulations were done, and conclusions regarding the meteorites were made. Through this method, researchers have been able to trace the origin of around 90% of known meteorites.
The research has allowed experts to find the origin of large asteroids that could pose danger to the planet, Earth reported. Ryugu and Bennu are two asteroids, that are being monitored by scientists because of the possibility, that they could enter the Earth in the future. Hayabusa2 (Japanese Aerospace Exploration Agency JAXA) and OSIRIS-REx (NASA) missions sampled these asteroids, and after analysis, it was revealed that they belong to the same parent asteroid as the Polana family.
The next plan of action for the researchers is to characterize all young families formed less than 50 million years ago, Earth reported. They want to focus on less-studied asteroid families, with hopes of identifying the origin of the remaining 10% of the meteorites. They are optimistic that this examination will aid them in knowing more about the nature of meteorites that have struck the planet or are set to enter it.