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Using magnetism, scientists at the University of Rochester first determined when carbonaceous chondrite asteroids first arrived in the inner solar system. Carbonaceous chondrite asteroids are enriched in water and amino acids.
This analysis offers valuable insights into the data that help inform scientists about the early origins of the solar system and why some planets, such as Earth, became habitable and could support living conditions, while other planets, such as Mars, did not. .
John Tarduno, William R. Kenan, Jr., professor in the Department of Earth and Environmental Sciences and Dean of Research for the Arts, Sciences and Engineering at Rochester said: “There is special interest in defining this story – about the huge number of exoplanet discoveries – to infer whether the events may have been similar or different in the exosolar systems. This is another component of the search for other habitable planets. “
Studying the magnetization of meteorites can offer a better idea of when objects formed and where they were early in the history of the solar system.
Tarduno said, “We realized several years ago that we could use the magnetism of asteroid-derived meteorites to determine the distance of these meteorites from the sun when their magnetic minerals were formed.”
Scientists studied magnetic data collected by the Allende meteorite, which fell to Earth and landed in Mexico in 1969. The Allende meteorite is the largest carbonaceous chondrite meteorite found on Earth. It contains minerals – calcium-aluminum inclusions – believed to be the first solids formed in the solar system.
To determine when the objects formed and where they were, scientists initially addressed a meteorite paradox that confused the scientific community: How did meteorites get magnetized?
Rochester graduate student Tim O’Brien, the first author of the article, found that the magnetic signals interpreted by previous scientists did not actually come from a core. Instead, magnetism is a property of Allende’s unusual magnetic minerals.
After solving this paradox, O’Brien was able to identify meteorites with other minerals that could faithfully record the first magnetizations of the solar system.
This work was later combined with the theoretical work of Eric Blackman, professor of physics and astronomy, and computer simulations led by graduate student Atma Anand and Jonathan Carroll-Nellenback, a computational scientist at Rochester’s Laboratory for Laser Energetics. These simulations showed that solar winds enveloped the first bodies of the solar system, and it was this solar wind that magnetized the bodies.
Using these simulations and data, the scientists determined that the parent asteroids from which the carbonaceous chondrite meteorites broke off arrived in the asteroid belt from the outer solar system about 4,562 million years ago, within the first five million years of the system’s history. solar.
Tarduno says that analysis and modeling offer more support for the so-called grand tack theory of Jupiter’s motion. While scientists once thought that planets and other planetary bodies formed from dust and gas at an ordered distance from the sun, today scientists realize that the gravitational forces associated with giant planets, such as Jupiter and Saturn, can drive the formation. and the migration of planetary bodies and asteroids. The grand tack theory suggests that the asteroids were separated by the gravitational forces of the giant planet Jupiter, whose subsequent migration then mixed the two groups of asteroids.
Journal reference:
- O’Brien, T., Tarduno, JA, Anand, A. et al. Arrival and magnetization of carbonaceous chondrites in the asteroid belt before 4562 million years ago. Commun Earth Environ 1, 54 (2020). DOI: 10.1038 / s43247-020-00055-w
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