Using samples collected by Japan Aerospace Exploration Agency’s (JAXA) asteroid explorer Hayabusa2, scientists have found the effects of micrometeoroid bombardments on asteroid 162173 Ryugu. The team used a technique called electron holography to study the sample’s magnetic properties, to learn about the magnetic field in the early solar system, and how space weathering affected the asteroid’s surface. Space weathering is the name astronomers use to describe changes to the surface of planetary bodies without an atmosphere, such as the Moon, Mercury, or asteroids like Ryugu, caused by meteoroid impacts or other influences from space.
Most meteorites that land on Earth’s surface are not suitable for studying space weathering, as the material originated in an asteroid’s interior. Some meteorites do contain material from an asteroid’s surface, but their properties are changed by the heat from atmospheric entry and the environment on Earth.