Asteroids, meteorites, and comets

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ASTEROIDS,
METEORITES,
AND COMETS
Created by:
Jennifer Holloway
Grade 5 Teacher
Westernport Elementary School
Information for this PowerPoint obtained
from:
• NSTA Online Module: Solar System:
Asteroids, Comets, and Meteorites
•NASA
•ESA
•Windows2Universe.org
This is a meteorite that had been broken off
of Mars from a large impact meteorite. It
spent millions of years in space before
landing in Antarctica.
Meteor Showers and Comets
Common Characteristics of
Comets, Meteoroids, and
Asteroids
 Most are “leftovers” from the formation of
the Solar System.
 Most didn’t form into planets themselves,
nor were they part of the planets that did
form.
 Each contains rocky material.
Differences in Comets,
Meteoroids, and Asteroids
Comets have a great amount of icy material covering
them because they are found at the far edge of the Solar
System.
Meteoroids are very small rocky bodies that are found
mostly near the orbits of planets. In fact, the meteor
showers that we observe from Earth’s surface occur as
Earth passes through a large concentration of them.
Asteroids contain little icy material and are much
larger than comets. Most are found between the orbits of
Mars and Jupiter.
Asteroids
Was there a missing planet between Mars and
Jupiter?
The space between Mars and Jupiter where all of the asteroids are is called the
ASTEROID BELT.
Asteroid Belt Location
A Closer Look At Asteroids
Eros, the second largest
near- Earth asteroid is 33
km long and 13 km wide.
Asteroid Belt Motion
Asteroids are objects composed of a combination of
metallic and rocky material. One of their defining
characteristics is that they are much smaller than
planets.
Barringer Crater (Meteor
Crater)
Winslow, Arizona
Meteors, Meteorites, Meteoroids
The name depends on the location.
Meteoroid-small bits of debris from an asteroid or comet that orbit the Sun.
Meteor-When a meteoroid enters the atmosphere of a planet at high speed and
friction causes it to burn up.
Meteorite-If the meteoroid does not burn up completely in the atmosphere and
collides with the surface. It is the piece that is left.
Comet Debris-Meteor Shower Simulation
The meteorites we find on
Earth could have been which of
the following?
material left over from when the Solar System formed
 broken off piece of an asteroid
 piece of a star that has died and fallen to Earth
 debris trail from a comet
 part of a terrestrial planet or the Moon

What happens to meteors as
they fall through Earth's
atmosphere?
 They fall through the atmosphere without any
change in size, mass, or appearance.
 They burn up due to friction as they move
through the atmosphere at high speeds.
 They combine together due to gravity to form
larger pieces of debris.
They get stuck in the upper part of the
atmosphere and never reach the surface.
A Closer Look at Comets
The Mawangdui silk, a 300 B.C. Chinese text of comet observations.
Comet Composition and Size
Comets are
basically dirty
snowballs!
Comet Kohoutek
•Rocky Core
•Gases condense on the
surface and freeze
Comet Hale-Bopp
A Comet’s Orbit
What characteristics do comets and asteroids
share?
 Both contain rocky material.
 Both originate from the edge of the Solar
System.
Both were formed from planets.
Their orbits are much more erratic than
planets.
The Life of a Comet
See an
animation of
the life of a
comet.
The Kuiper Belt
The outer edge of our Solar System is not empty. There are many, many huge
spheres of ice and rock out near Pluto's orbit. Astronomers call this huge group
of planetoids "Kuiper Belt Objects", or "KBOs" for short. The Kuiper Belt is a bit
like the asteroid belt, but much farther from the Sun. See how they are out
past Neptune and Pluto?
What might you predict about
the formation of asteroids,
meteorites, and comets?
 Some of them could be the oldest bodies in
the Solar System.
 Asteroids, comets, and meteorites did not
form around the same time.
 They contain material that formed from the
planets.
 They formed at the same time as the planets.
Flight of a Comet
EPOXI mission has successfully flown by comet Hartley 2.
Mercury's Caloris Basin taken by Mariner 10 in
1974. Image courtesy: NASA/JPL-Caltech.
Densely cratered surface of Mercury as seen by
Mariner 10 in 1974. Image courtesy: NASA/JPLCaltech.
Impact craters near Mars' Promethei Terra region
(top) and the Acheron Fossae region (bottom).
Images courtesy: NASA/JPL-Caltech.
Heavily cratered surface of Mars' polar
region. Image courtesy: NASA/JPL-Caltech.
The Mare Oriental region of the Earth's
Moon shows several impact craters. Image
courtesy: NASA.
The heavily cratered South Pole of the Moon as seen from
the Clementine spacecraft. Image courtesy: NASA.
What could’ve created these
craters?
Volcanic Processes
Comets
Meteoroids
Asteroids
Meteoroid Hitting the Moon
Click for Video
Collisions With Planets
Mosaic of images showing the evolution of the ShoemakerLevy 9 G (a comet) impact site on Jupiter in 1994. Images
not to scale. Image courtesy: NASA/JPL-Caltech/STScI.
Impacting Earth
Clearwater Lakes in
Quebec, Canada.
Created by an asteroid
290 million years ago.
Wolf Creek crater in Australia.
Created by an asteroid impact
approximately 300,000 years ago.
Which of the following are
characteristics of a
meteorite?
 found on Earth’s surface after partially burning
up in the atmosphere
 found between Mars and Jupiter
 have erratic orbits that bring them near the Sun
 originate in the outer Solar System
 composition can be rocky or metallic
 a smaller piece of another body such as a planet
Which of the following are
the characteristics of an
asteroid?
 often found between Mars and Jupiter
 found on Earth’s surface after partially burning up
in the atmosphere
 originate in the outer Solar System
 a smaller piece of another body
 composition is similar to the terrestrial planets
 Have erratic orbits that bring them near the Sun
Which of the following are
characteristics of a comet?
 found on Earth’s surface after partially
burning up in the atmosphere
 often found in the outer Solar System
 found between Mars and Jupiter
 a smaller piece of another body
 have erratic orbits that bring them near the
Sun
 has an icy cover made of gases also found in
the gas giant planets
Summary
Comets are icy bodies composed of rock, dust, and ice.
Asteroids are large bodies somewhat similar to planets.
Meteoroids are pieces of these larger bodies that have
been show to be the oldest bodies in the Solar System.
Assess and Wrap-Up
 Quiz
 A Meteorite Game
Download
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