3. Comets
• Description: Cold clumps of gases and
dusty ice from the outer parts of the solar
system
• Comet means long haired star
• Called “Dirty Snowballs”
6. Parts Explained
• Nucleus – mass of ice and frozen gas
• Coma – cloud of gas that surrounds the
nucleus
• Tail – formed when the comet travels near
the sun; it’s the nucleus vaporizing
7. Comet Orbits
• Comets have long, narrow elliptical orbits
• Short period comets are found in the Kuiper
Belt
• Long period comets are found in the Oort
Cloud
• Sometimes, comets get too close to the sun,
and then…
16. Asteroids
• Description: Rocky remains from the
formation of the solar system
• Notable Asteroids:
– Ceres – now a dwarf planet, only one in the
asteroid belt
– Vesta – can be seen without a telescope
17. Asteroids
• Composition:
– Rocky, iron, or rocky-iron
• Location/Orbit:
– Asteroid Belt – between Mars and Jupiter
– Trojans – orbit with a planet
– Near Earth Asteroids – cross the Earth’s orbit
19. Asteroids
• Size: Varies from a few hundred feet to a
few hundred miles
• Jupiter’s relationship with asteroids:
– Scientists believe the asteroid belt is the
remains of a planet that never formed because
of Jupiter’s gravity
• Evidence asteroids have hit planets:
– Impact craters like the one thought to have
caused the dinosaur extinction
21. Asteroids Summary
• Not all asteroids are located in the asteroids
belt and can pass near Earth
• Jupiter’s gravity kept the asteroids from
forming a planet
• Some asteroids orbit just before and after
Jupiter
• Largest asteroid, Ceres, is 580 mi across but
most are less than a few miles across
22. Asteroid Impacts Summary
• Scientists think an asteroid impact near
Mexico caused the dinosaur extinction.
• Chicxulub Crater in Mexico
• Video
25. Meteors
• Description: Rocky or metal debris in
space; most no bigger than a pebble
• Meteoroid: a small chunk of rock or dust in
space
• Meteor: a streak of light in the sky
produced by the burning of a meteoroid in
Earth’s atmosphere
• Meteorite: a meteoroid that has hit Earth’s
surface
26. Meteoroids
• Meteoroids are small chunks of rock and
dust left over from asteroids and comets
that pass by the Earth.
• Composition: rocky, iron, or mixed
• Location/orbit: Found within the path of the
Earth’s orbit around the sun.
27. Meteoroids
• Types:
– Stony
– Iron
– Stony-Iron
• Meteor Shower: yearly predictable meteors
when Earth passes through comet or
asteroid debris
28. Meteors
• 3 types:
• Meteor: a streak of light in the sky
produced by the burning of a meteoroid in
Earth’s atmosphere
• Meteoroid: a chunk of rock or dust in space
• Meteorite: a meteoroid that has hit Earth’s
surface
Meteor Impact Crater in
Arizona.
