Researchers uncover key clues to the history of the solar system

New clues lead to a better understanding of the evolution of the solar system and the origin of the Earth as a habitable planet.

In a new article published in the journal Nature Communications Earth and Environment, researchers at the University of Rochester were able to use magnetism to determine, for the first time, when asteroids-rich asteroids arrived for the first time. water and carbonaceous chondrite amino acids. in the inner solar system. The research provides data that helps inform scientists about the early origins of the solar system and why some planets, such as Earth, became habitable and were able to sustain conditions conducive to life, while other planets, such as Mars, no.

The research also provides scientists with data that can be applied to the discovery of new exoplanets.

“There is a special interest in defining this story, in reference to the enormous number of exoplanet discoveries, to deduce whether the events could have been similar or different in the exo-solar systems,” says 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. “This is another component of the search for other habitable planets.”

Solving a paradox using a meteorite in Mexico

Some meteorites are pieces of debris from outer space objects such as asteroids. After separating from their “parent body”, these pieces are able to survive by passing through the atmosphere and eventually hit the surface of a planet or moon.

Studying the magnetization of meteorites can give researchers a better idea of ​​when objects formed and where they were early in the solar system’s history.

“We realized several years ago that we could use the magnetism of asteroid-derived meteorites to determine how far these meteorites were from the sun when their magnetic minerals were formed,” says Tarduno.

To learn more about the origin of meteorites and their parent bodies, Tarduno and the researchers 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 and contains minerals – calcium-aluminum inclusions – thought to be the first solids formed in the solar system. It is one of the most studied meteorites and has been considered for decades to be the classic example of a meteorite from a primitive parent body of an asteroid.

To determine when the objects formed and where they were, the researchers first had to address a meteorite paradox that was confusing the scientific community: How did meteorites get magnetized?

Recently, a controversy arose when some researchers proposed that carbonaceous chondrite meteorites like Allende were magnetized by a central dynamo, such as that of Earth. The Earth is known as a differentiated body because it has a separate crust, mantle and core in composition and density. Early in their history, planetary bodies can gain enough heat so that there is diffuse melting and the dense material – iron – sinks in the center.

New experiments by Rochester graduate student Tim O’Brien, the paper’s first author, found that the magnetic signals interpreted by previous researchers did not actually come from a core. Instead, O’Brien found, magnetism is a property of Allende’s unusual magnetic minerals.

Determination of the role of Jupiter in the migration of asteroids

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.

Tarduno’s magnetic group then combined this work 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 researchers 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.

He adds: “This initial movement of carbonaceous chondrite asteroids sets the stage for further dispersal of water-rich bodies, potentially on Earth, later in the development of the solar system, and could be a common pattern for exoplanetal systems.”

/ Public release. The material in this public publication is from the original organization and may be of a temporary nature, modified for clarity, style and length. View full here.