micrometeoroid

1. The inflatable spars, for example, will not remain rigid for long because of the inevitable micrometeoroid impacts.
   举例来说，可膨胀伸出的帆桅，由于无法避免微流星体的撞击，因此无法长久保持坚硬的状态。

noun

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

   Synonym:    micrometeoritemicrometeor