微陨石是在地球表面收集到来自地球之外的小天体，大小范围从50微米至2毫米。微陨石是进入地球大气层而幸存下来的流星尘。它们从大小、组成都与陨石不同，并且数量、种类更为丰富，其中也包括较小的星际尘埃的颗粒（IDPs），是宇宙尘的一部分。流星体以高速（至少11Km/s）进入地球的大气层，经过加热和大气的磨擦和压缩。目前已经在地球上搜集到，来自地球之外个别微陨石的质量在10和 10公克之间。 弗雷德·惠普尔首先创造了微陨石这个名称来描述落在地球上如灰尘大小的天体。有时，陨石和微陨石在进入地球大气层时是被看见的流星，但不论它们能否墬落到地球表面被找到，陨石和微陨石依然都存在着。

A micrometeorite is an extraterrestrial particle, ranging in size from 50 µm to 2 mm, collected on the Earth's surface. Micrometeorites are micrometeoroids which have survived entry through the Earth's atmosphere. They differ from meteorites in being smaller, more plentiful and different in composition and are a subset of cosmic dust, which also includes the smaller interplanetary dust particles (IDPs). Micrometeorites enter the Earth's atmosphere with high velocities (at least 11 km/s) and undergo heating through atmospheric friction and compression. Individual micrometeorites weigh between 10 and 10 g and collectively contribute most of the extraterrestrial material that has come to the present day Earth. Fred Lawrence Whipple first coined the term "micro-meteorite" to describe dust-sized objects that fall to the Earth. Sometimes meteoroids and micrometeoroids entering the Earth's atmosphere are visible as meteors or "shooting stars", whether or not they reach the ground and survive as meteorites and micrometorites.