Dating antarcic meteorites
For instance, meteorite fragments have been found in samples returned from the Moon, and the robotic rover Opportunity has identified at least one meteorite on the surface of Mars.The largest meteorite that has been identified on Earth was found in 1920 in Namibia and was named the Hoba meteorite.A better approach to finding meteorites than searching places with few rocks, however, is to search places where they can accumulate over time—i.e., where the surface is quite old and rates of weathering are low.Because meteorites contain minerals, such as iron metal, that are easily weathered, they do not normally last long on Earth’s surface.
The assembly of planet-sized bodies from this dust almost certainly involved the coming together of smaller objects to make successively larger ones, beginning with dust balls and ending, in the inner solar system, with the rocky, or terrestrial, planets—Mercury, Venus, Earth, and Mars.
Until quite recently, there were no systematic efforts to recover them.
This was largely because meteorites fall more or less uniformly over Earth’s surface and because there was no obvious way to predict where they would fall or could be found.
The primary ones were decay of short-lived radioactive isotopes within the bodies and collisions between the bodies as they grew.
As a result, the interiors of larger bodies experienced substantial melting, with consequent physical and chemical changes to their constituents.