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The streaks of light we sometimes see in the night sky and call meteors were not identified as interplanetary rocks until the 19th century. Before then, the streaks of light were considered only one of a variety of atmospheric phenomena, all of which bore the name meteor. Rain was an aqueous meteor, winds and storms were airy meteors, and streaks of light in the sky were fiery meteors. This general use of meteor survives in our word meteorology, the study of the weather and atmospheric phenomena. Nowadays, astronomers use any of three words for rocks from interplanetary space, depending on their stage of descent to the Earth. A meteoroid is a rock in space that has the potential to collide with the Earth's atmosphere. Meteoroids range in size from a speck of dust to a chunk about 100 meters in diameter, though most are smaller than a pebble. When a meteoroid enters the atmosphere, it becomes a meteor. The light that it gives off when heated by friction with the atmosphere is also called a meteor. If the rock is not obliterated by the friction and lands on the ground, it is called a meteorite. For this term, scientists borrowed the –i�ٱ� suffix used in the names of minerals like malachite and pyrite.