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METEORITES – What are they?. Meteorites are chunks of extra-terrestrial matter from outer space that land on Earth. Rocks from Outer Space!. Where do they come from?.
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METEORITES – What are they? Meteorites are chunks of extra-terrestrial matter from outer space that land on Earth. Rocks from Outer Space!
Where do they come from? Most meteorites come from the asteroid belt that exists between the orbits of Mars and Jupiter. Collisions between asteroids can create more debris as well as knock some of this material out of the asteroid belt. This debris may get trapped in the gravitational pull of the Earth’s orbit and come slamming down onto the ground. Meteorites have also come from Mars and the Moon.
How do they get here? When this debris enters the Earth’s atmosphere, they turn into “shooting stars” or “meteors” and look like a white or bright streak of light that is hurtling across the sky. Since most meteors burn up in the atmosphere before they ever touch the ground, they usually don’t produce meteorites. Only the really big and bright meteors, the “bolides” or “fireballs”, have enough rocky stuff left over.
What are they made of? Meteorites from the asteroid belt are usually chondrites (or stony meteorites) and are most often made up of nickel-iron metal, pyroxene, and olivine.
How do we know they’re from Mars? From spectroscopic measurements, we know the chemical composition of Mars’ atmosphere. The chemical analysis done on the gas inside the rocks matched the chemical composition of Mars’ atmosphere, and voilà, we have Martian meteorites!!
How did they get here? A huge meteor or comet would have to have violently smashed into Mars surface and blasted off chunks of Mars at speeds of at least 11,000 miles per hour. That’s how fast a rock would have to be going to escape Mars’ gravity and land on earth.
What’s a Lunar meteorite? Sometimes the moon is hit by passing objects such as asteroids and comets. When an object is big enough and heavy enough, when it crashes into the moon, it can send chunks of the moon flying everywhere. Some of these pieces can land on earth as lunar meteorites, or lunaites .
On this lunaite, there are no sharp angles or edges in the portions of the meteorite covered by the fusion crust. But there are ablation scoops and pits.
