Transcript D.S.Q.:

 Comets
are known as what?
 The comet’s ion tail always extends
where?
 Most asteroids can be found in the ______
__________?
In your Table of Contents…
 Did
you add “Sun Notes” yesterday? If not,
please add that.
 For
today, add “Comets, Meteors, and
Asteroids Notes”
Comets, Asteroids, &
Meteors
In addition to planets and moons,
the solar system contains many
other types of objects, including
comets, asteroids, and meteoroids.
Comets
 BrainPop
Comets
A comet is a small body of
ice, rock, and cosmic dust
loosely packed together.
 Known as “dirty snowballs.”
 When a comet passes close
enough to the sun, solar
radiation heats the water ice
so that the comet gives off
gas and dust in the form of a
long tail.
 The ion tail consists of
electrically charged particles
of gas.

Comet Orbits
 The difference between the orbit of a planet
and the orbit of a comet is that a comet's
orbit is highly elliptical and a planet's orbit is
only slightly elliptical, but more circular.
 The comet’s ion tail always extends away
from the sun.
 This is because the ion tail is blown away
from the sun by the solar wind.
 When the comet Shoemaker-Levy
9 broke apart and fell into Jupiter,
some of the fragments generated
explosions that produced fireballs
larger than Earth.
 Switch
composition notebooks with your
neighbor. On their planetary placement
page, write one fact about Comets under
the chart of the planets. Be sure you label
it “comets” for them. Then, switch back
and stand up.
 Asteroids
Asteroids

Asteroids are small,
rocky bodies in orbit
around the sun.
 Have irregular shapes
 Most asteroids orbit the
sun in a wide region
between the orbits of
Mars and Jupiter, called
the asteroid belt.
Add to the bottom of your notes page…
Types of Asteroids




Outer region of the
asteroid belt = dark
reddish brown to black
surfaces
A little closer to the sun =
dark gray surfaces
Innermost part of the belt =
light gray asteroids
Examples: Hektor, Vesta,
and Ceres
 Under
comets on your planetary
placement, add one fact about Asteroids.
Be sure to label it “asteroids.”
 Stand up when you are finished.
Meteoroids
A meteoroid is a small,
rocky body orbiting the
sun.
 Meteoroids are similar
to asteroids, but they
are much smaller.
 In fact, meteoroids
probably come from
asteroids.

Meteoroids
If a meteoroid enters Earth’s atmosphere and strikes the
ground, it is then called a meteorite.
 Stony, metallic, and stony-iron are the three major types of
meteorites.
 It travels at such high speeds that it heats up and melts.
 As it burns up, the meteoroid glows red hot and gives off an
enormous amount of light.
 From the ground we see a streak of light or shooting star.
 The bright streak of light caused by a meteoroid or comet dust
burning up in the atmosphere is called a meteor.
 Some meteors that hit the ground can cause craters.

Meteor Crater
Planets and moons that have no atmosphere have
many more impact craters than those that do have
atmospheres.
 Earth’s atmosphere acts like a shield.

 In 1954, Mrs. E. Hulitt Hodge, of
Alabama, was struck by a meteorite
as she was taking her afternoon
nap. Bruised, but not badly
injured, she is one of only two
people known to have been struck
by a meteorite.