Japan probe finds scars of micrometeoroid bombardment on asteroid Ryugu

Analysis of asteroid Ryugu samples hints at its surface property changes over time, some most likely due to collisions with micrometeoroids. 

A micrometeoroid refers to a particle tinier than a grain of sand. As per NASA, millions of micrometeoroids strike Earth’s atmosphere every day.

However, the majority of them never make it to the Earth’s surface as they get vaporized upon entering the atmosphere.