MadSci Network: Astronomy |
G'day! Yes, there is an explanation for the colors you see as meteoroids vaporize. (Incidentally, if a meteoroid (or meteor) hits the ground, then it is known as a meteorite). Two of the major factors for a meteoroid's color are speed and composition. During its trip through the atmosphere, meteoroids collide with air molecules, knocking away materials and stripping electrons from the meteor. When the stripped atoms recapture electrons, light is emitted. The color of the light depends on the temperature and the material affected. So the faster the meteoroid hits our atmosphere, the brighter it will usually glow. Here's a quick table of elements commonly vaporized in our atmosphere as meteoroids disintegrate: Element Color Sodium Orange-Yellow Iron Yellow Magnesium Blue-Green Calcium Violet Silicon Red I'm also told that red meteors which appear as very long streaks are more than likely skimming the atmosphere, like a flat rock on water. Oh, yeah, and green meteors occasionally show up too. These are usually quite bright. Ionized oxygen may cause the green color. In fact, I'm told it's a similar phenomenon to the famous green flash that occurs just as the sun dips below the horizon on Maui, Hawaii. I hope this helps a bit. Steve Cartoon Web Engineering, Edmark Corporation
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