Transcript space-rocks - WLWV Staff Blogs

SPACE ROCKS!
By: Jordan, Keaton, and Vanessa
Asteroids
• ASTEROIDS
• Asteroids are rock fragments left over from the formation of
the solar system about 4.6 billion years ago. Most asteroids
orbit the sun in a belt between Mars and Jupiter. Scientists
think there are probably millions of asteroids, ranging widely in
size from hundreds of kilometers wide. Occasionally, asteroids’
orbital paths are influenced by the gravitational tug of planets,
which cause their paths to alter. Scientists believe stray
asteroids have slammed into the Earth in the past, playing a
major role in the evolution of our planet.
METEORS AND METEORITES
• While traveling through space, asteroids sometimes collide with each other and
end up breaking into smaller rock fragments. Comets shed dust as they fly
through the solar system. These collisions result in numerous small particles
and fragments, called meteoroids. Meteoroids are usually found orbiting the
Sun.
• Most meteoroids are small and rocky; when they approach the Earth they burn
up upon entering the atmosphere. This usually results in a meteor also known
as a shooting star.
• Fireballs are larger meteoroids, roughly ranging in size from anywhere from a
basketball to a Volkswagen beetle. They also make very impressive sky displays
as they break into fragments and burn up on their journey through the
atmosphere.
• Not all meteoroids burn up though; some make it through the atmosphere and
impact the earth. These are called meteorites.
COMETS
• Comets are relatively small, fragile, irregularly shaped rocks, and often
resemble asteroids in the sense that they are made from left over break
offs from the solar system formation. Comets however are icy dirtballs that
form in the outer solar system. The icy surface is embedded with dust, grit,
and other particles from space.
• Many comets have elliptical orbits that cut across the orbits of planets,
making them come very close to the sun and then swinging them far away.
Some of the more distant comets can take more than 30 million years to
complete one orbit. Some of the comets with smaller orbital paths can take
less than 200 years.
• When far away from the sun, comets are very cold, icy dirtballs. As they
approach the sun their surface begins to warm and volatile minerals begin
to vaporize. The vaporizing gases carry small duct grains with them which
can result in a bright shining tail trailing behind the comet.