When a meteoroid enters the atmosphere, it compresses the air in front of it.

当流星体进入大气层，它压缩的空气在前面的。

When a meteoroid enters the atmosphere of the earth (becoming a meteor), it is actually the speed compressing the air in front of the object that causes it to heat up.

流星体闯入地球的大气层（变成流星之前）时，由于高速飞行，它的前端与空气强烈摩擦发热。

The cometary ejection play a crucial role in formation and evolution of the meteoroid stream.

彗星的喷发速度在流星群的演化过程中起着重要作用.

Hypervelocity impact of meteoroid and space debris on spacecraft can lead to significant damage and catastpphic failure.

微流星和空间碎片是现在任何使命航天器的公认威胁。