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Asteroids
and Their Main Belt: |
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Also known as “minor
planets” or “planetoids,” asteroids are medium-sized rocky
objects which orbit the Sun. They’re smaller than a planet, but
bigger than a meteoroid. A good concentration of them is found
in the Asteroid Belt – a doughnut-shaped region between the
orbits of Mars and Jupiter.
Thousands of Asteroids
In this “belt” are some 40,000 asteroids, ranging in size from
one mile to nearly 600 miles in diameter. The largest of these
is indeed 1 Ceres, which measures 578 miles across and along
with 4 Vesta, 2 Pallas, and 10 Hygiea, account for more than
half of the belt’s surface.
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Discovered on January 1, 1801, 1 Ceres was the first asteroid to
be identified, named, and catalogued. Since, there have been
over 2,000 other asteroids in the belt successfully numbered.
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How Did the Belt
Form: |
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There are
several theories – just as there are for the formation of the
Solar System itself – but the most widely accepted is the
nebular theory. According to theory, the Solar System was at one
time shapeless, aimless, until an explosion occurred that set
everything in motion.
Post-explosion, as the Solar System’s eight planets formed from
planetesimals, something happened between Mars and Jupiter that
prevented the Asteroid Belt from turning into its own major
planet.
Likely, it was the gravitational pull from sizeable Jupiter that
disrupted the planetesimals of the potential new (Asteroid Belt)
planet. Instead of sticking together and accreting, these
planetesimals crashed into each other and broke apart – making
them too small to form a planet.
Instead, the asteroids formed a belt.
Note: The Asteroid Belt is also known as the “main belt,” as a
way of identifying it from similar concentrations in the Solar
System, such as the Kuiper Belt. |
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