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Level Physics Notes: Cosmology – The Asteroid Belt
The asteroid belt is a region of space
between Mars and Jupiter, consisting mostly of rocky bodies almost
the size of our moon down to dust particles. More than half the mass
of the belt is due to four asteroids - Ceres, Vesta, Pallas, and
Hygiea, and the total mass of the belt is less than the mass of our
moon, but there are still probably at least 40,000 asteroids that are
more than 0.5 miles across – enough to put a bloody big dent in
the Earth.
Despite the popular image, the asteroid
belt is virtually empty, just less empty than the sapace around it.
Spacecraft have passed through it undamaged.
It is believed that the planets were formed by a process of
accretion, with smaller bodies colliding and forming larger bodies,
eventually becoming large enough to gravitationally attract matter
around them. The asteroid belt consists of the left over pieces that
have never joined a planet
Much of what we know about the asteroid belt is gathered from
asteroids that have hot the Earth. From this and other evidence we
can deduce the temperature, composition and temperature gradient of
the early solar system.