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Meteorites III

StarDate: 
April 19, 2015

The Lyrid meteor shower is building toward its peak on Tuesday night. The best views come in the wee hours of the morning, when your part of Earth turns most directly into the meteor stream. And there’s no moonlight to spoil the view.

The meteors are particles of rock from a comet. They splash into Earth’s atmosphere at blazing-fast speeds, so they vaporize as streaks of light.

The particles in a meteor shower are so small that they completely burn up. But a few random meteors are big enough to survive their fiery plunge and reach the surface. Such survivors are known as meteorites.

Thousands of meteorites hit Earth each year. Most plop into the oceans or onto rocky terrain where they’ll likely never be found. A few are discovered — although it generally takes an expert to identify them.

In fact, most meteorites don’t look unusual at all. They’re fairly angular, although their edges may have been rounded by their plunge through the atmosphere. They’re generally fairly smooth, with no pits on their surfaces. Those that have fallen recently are covered with a shiny black layer known as a fusion crust.

Most meteorites contain large amounts of iron, so they’re attracted to a magnet. And most also contain small, round blobs of once-molten rock — a feature not found in Earth rocks.

Most rocks that people think are meteorites are just ordinary Earth rocks. But a rare few really are rocks from outer space.

 

Script by Damond Benningfield, Copyright 2015

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