My OperaA Speck of Comet
Saturday, September 3, 2011 6:04:21 AM
To capture comet dust NASA sends up special high-altitude airplanes with sticky collection trays. Up high, some of the dust that it picks up comes from space.
Comet particles are about .1 millimeters (.004 inches) in size. Chemically, they resemble some meteorites found on Earth but have a fluffy structure made of millions of tiny crystals stuck together, quite different from any meteorite we have seen.
The gases trapped inside the specks prove they come from space. Comets are basically dirty snowballs, and when they come close to the Sun, they are heated. Bits of comet vaporize, forming a giant tail. Gas and dust are spread throughout the tail, and sometimes the Earth passes through the tail.
The larger dust particles burn up in the atmosphere, forming streaks we call meteors, but sometimes little dust grains like this one can survive entry into our atmosphere.
Comet particles are about .1 millimeters (.004 inches) in size. Chemically, they resemble some meteorites found on Earth but have a fluffy structure made of millions of tiny crystals stuck together, quite different from any meteorite we have seen.
The gases trapped inside the specks prove they come from space. Comets are basically dirty snowballs, and when they come close to the Sun, they are heated. Bits of comet vaporize, forming a giant tail. Gas and dust are spread throughout the tail, and sometimes the Earth passes through the tail.
The larger dust particles burn up in the atmosphere, forming streaks we call meteors, but sometimes little dust grains like this one can survive entry into our atmosphere.
