meteoroid stream

The annulus of meteoroids around the orbit of a decaying comet. Dust particles are pushed away from the cometary nucleus by gas pressure at the time when the nucleus is near perihelion. The particles then have slightly different orbital parameters to the comet. Stream-formation time depends on perihelion distance and meteoroid size, being anything from tens to hundreds of years. New streams only have meteoroids close to the parent comet and only produce meteor showers periodically. Streams are about 100 times thicker at aphelion than at perihelion. They contain anywhere between 10¹⁴ grams and 10¹⁷ grams of dust and have volumes in the range 10²¹ to 10²⁵ km³.

单词	meteoroid stream
释义	meteoroid stream meteoroid stream The annulus of meteoroids around the orbit of a decaying comet. Dust particles are pushed away from the cometary nucleus by gas pressure at the time when the nucleus is near perihelion. The particles then have slightly different orbital parameters to the comet. Stream-formation time depends on perihelion distance and meteoroid size, being anything from tens to hundreds of years. New streams only have meteoroids close to the parent comet and only produce meteor showers periodically. Streams are about 100 times thicker at aphelion than at perihelion. They contain anywhere between 10¹⁴ grams and 10¹⁷ grams of dust and have volumes in the range 10²¹ to 10²⁵ km³.
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