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.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006
References in periodicals archive ?
We see a shower when Earth, in its annual travels around the Sun, passes through a meteoroid stream strung along a comet's orbit.
Consequently, after a comet has returned many times to perihelion, the meteoroid stream will consists of a large number of separate individual dust trails.
Meteor Shower--A regular (typically annual) event in which the orbit of Earth intersects that of a meteoroid stream, causing a number of meteors with approximately parallel trajectories appearing to emanate from the same radiant.
EST, when Earth intercepted a meteoroid stream that astronomers believe the comet ejected in 1767.
Every year as the Earth circles the Sun we pass through the Leonid meteoroid stream around November 17th.
FOR SEVERAL DAYS around October 21st every year, Earth passes through the Orionid meteoroid stream: sparse, widely scattered bits of Halley's Comet.
The title of the study describes the new branch of the Taurid meteoroid stream as a "real source of potentially hazardous bodies."
Such events, known as meteor showers, are common; our planet travels through about 12 a year, each from a meteoroid stream spewed by a different comet.
But because the comet--and the meteoroid stream all along its orbit--have made hundreds of trips around the Sun over tens of thousands of years, slight periodic perturbations can add up.
A Leonid storm occurs once every 33 years, when Earth passes through the meteoroid stream shortly after Temple-Tuttle has neared the sun and spewed fresh particles.
Complicating things, mass sorting in the meteoroid stream means that faint meteors are their most abundant before the visual peak, and bright ones after.