micrometeorite

A tiny particle of meteoric dust, especially one of many that fall to the surface of the earth or moon.

A meteorite so small that it drifts down to Earth without becoming intensely heated in the earth’s atmosphere.

an extraterrestrial particle, less than a millimeter in size, that has survived entry into the atmosphere without melting

a meteorite or meteoroid so small that it drifts down to earth without becoming intensely heated in the atmosphere