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Nearly every meteorite that falls on Earth can ultimately come from half a dozen lost worlds that separated shortly after the birth of the solar system, reveals a new study.
This discovery could shed light on the nature of dangerous asteroids that could one day hit the Earth, which could in turn reveal the best ways to deflect them.
Astronomers have discovered more than 400,000 asteroids in the main asteroid belt between Mars and Mars. Jupiter, the researchers of the new study told Space.com. The main source of meteorites that hit Earth is the inner main belt, which contains about one-third of the asteroids in the belt, they noted. [The Asteroid Belt Explained: Space Rocks by the Millions (Infographic)]
Previous research has found that many asteroids appear to have orbits and similar compositions, and that every "family of asteroids" is formed when a collision has broken a body of the size of a planet in several fragments.
Up to now, scientists had suggested that only about 44 percent of the asteroids in the inner main belt belonged to five families of asteroids, each named after their largest body – Flora , Vesta, Nysa, Polana and Eulalia.
Researchers find that almost all the asteroids in the inner main belt belong to either the five main families, or members of scattered old 'ghost' families.
"We think that the inner third of the asteroid belt comes from around." Dermott and his colleagues analyzed asteroids in this region that had not previously been classified in any family. asteroid ". Dermott and his colleagues analyzed asteroids in this region. They focused on the characteristics of their orbits, such as their oval or eccentric shape, or their inclination or inclination with respect to the sun's equator.
The researchers found that about 85% of the asteroids in the inner main belt belonged to the five major families of asteroids. The remaining 15 percent also belonged to these five families or, more likely, came from a few ghost families, they said.
These new discoveries shed light on the origins of most meteorites that hit the Earth. "Scientists have these wonderful meteorite collections, and they are all slightly different," said Dermott. "The big question was," Are these differences in meteorites because they come from a large number of different objects, or because they come from a few objects that have evolved? with time? "We say that these meteorites usually come from a small number of objects large enough, hundreds of kilometers in diameter or more."
The breakup of about five large bodies of the early solar system could have contributed to most asteroids in the inner asteroid belt – those that would fall the Earth the most.
Credit: Don Davis
Future research may investigate asteroids of the middle and outer main belt, Dermott said. "There was probably a comparable number of body-parents for middle and outer belt asteroids as well as for inner belts," he says.
Dermott also wants to study how the rocks leave the main belt "and become close to the Earth asteroids and meteorites Now that we know where the objects of the inner belt come from, we can study the dynamics of their displacement under the influence of planets and radiation over billions of years. "
Asteroids near the Earth can potentially collide with the Earth, with disastrous consequences. "By learning more about the evolution of asteroids over time, it helps us learn what they are made of, and knowing what a near-Earth asteroid is doing will help us if we want to know how to deflect it. "Dermott says.
Scientists detailed their findings online July 2 in the journal Nature Astronomy.
Follow Charles Q. Choi on Twitter @cqchoi . Follow us on @Spacedotcom Facebook and Google+. Original article on Space.com.
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