What do chondrules look like up close? Click HERE

Carbonaceous Chondrites.These rare meteorites contain elemental carbon and other volatiles. In normal chondrites, these elements have been heated out. Thus, carbonaceous chondrites are more pristine, and are the least altered remains of the early solar nebula.

Achondrites (left) contain no chondrites. They have likely been heated sufficiently to melt any chondrites. Scientists believe that some of these meteorites originated on the surface of the Moon or Mars.

Why the different Stony Meteorites?
Different histories. Normal Chondrites are heated only enough to burn off volatiles but not destroy chondrites. Achondrites have been heated quite significantly. In fact, achondrites are quite difficult to separate from earth rocks, which have been similarly heated.

The Origin of Meteors
Very small particles of material are typically responsible for creating the meteors seen in the sky. These small bits of dusty debris predominantly come from comets. Over several billions of years, perhaps millions of comets have come through the inner solar system, leaving behind a debris trail as the ices holding them together melts near the Sun. On any given night, one might see several small meteors in an hour. If Earth's orbit happens to intersect the path of a recent comet, the debris trail will be dense, and one might see hundreds to thousands of meteors per hour. This is called a meteor shower.

Meteor Showers are among the most beautiful astronomical phenomenon to experience as an amateur astronomer. To find out about upcoming major showers, you should go to this site: http://comets.amsmeteors.org/

The origin of Meteorites
Recall, meteorites are bits of space debris that survive entry through Earth's atmosphere. These rocks are significantly more sturdy and dense than the fluffy dust specks responsible for typical meteors. Scientists studying the orbits of meteorites as the fall to earth have discovered that they point back towards the Asteroid Belt. Thus, meteorites (quite unlike meteors) originate from dense rock bits which were once parts of asteroids and in the last billion or so years, have broken off.