In 2020, Japan's Hayabusa2 spacecraft brought samples of an asteroid named Ryugu to Earth — and now, scientists examining those samples found that the object bears the scars of a recent encounter with tiny space rocks.
The reason the research team believes Ryugu was bombarded by micrometeorites is due to a fine layer of sodium, just 10 nanometers thick, on the surface of the asteroid's fragments. This kind of build-up is unusual because volatile elements like sodium, which can get exposed after an object is blasted with micrometeorites, are usually later depleted by solar winds blowing from the sun and the general influence of space.
