Spring Break Packet
Spring Break Packet
Spring Break Packet
Comets, Meteors, & Asteroids The Smaller Bodies in Our Solar System
Comets
We usually think of our solar system as the sun and the eight planets that orbit it. Comets,
asteroids, and meteoroids also belong to our solar system.
A comet is an icy body that orbits the sun. The center of a comet is called the nucleus. It is a
small, solid ball surrounded by gases, water, and dust. These things are frozen into a kind of
dirty snowball. The nucleus can be a few kilometers or a few miles in diameter. The cloud of
dust and gases around the nucleus is called the coma. Together, the nucleus and the coma
form the comets head. The third part of the comet is called the tail. Comets only have tails
when they are close to the sun.
Comets travel in large orbits around the sun. When they are far from the sun, they travel
about 2,000 miles per hour. As they get closer to the sun, they speed up. They may go as fast
as 100,000 miles per hour! As a comet approaches the sun, its icy body begins to melt. This
releases gas and dust. The solar winds push against the coma, making a tail that streams
from the nucleus. The tail of a comet may be millions of kilometers long. It is usually curved
because of the movement of the comet.
The tail of a comet is blown outward by the solar wind, so the tail always points away from the
sun. As the comet nears the sun, the tail is behind it. When the comet moves away from the
sun, the tail is in front of it. The tails of some comets are visible from Earth. As the comet
continues its orbit and gets farther from the sun, its tail disappears.
Some comets make many revolutions around the sun. The most famous is Halleys Comet.
Edmund Halley discovered it in 1682. It revolves around the sun once every 76 years. The tail
of Halleys Comet has been measured at about 93 million miles, the same distance from the
Earth to the sun. Halleys Comet last came near Earth in 1986 and will return in 2062. Other
comets make only one orbit before disappearing into outer space. Meteor showers sometimes
occur when the Earth passes through the dusty orbit of a comet.
Meteor showers are seen when the dust from the comet passes into Earths atmosphere. The
dust may have been left there in space for hundreds of years. Then we can see hundreds of
meteors in one night. Once a year in August and in November, Earth passes through the
spots where a comet left its dust. In August, the Perseid meteor shower is seen on Earth. The
Leonid meteor shower happens in November. As comets pass through the solar system, they
can be broken into pieces. In 1994, comet Shoemaker-Levy 9 was broken into 20 pieces by
Jupiter's gravity. Scientists watched as the pieces crashed into Jupiters atmosphere.
Asteroids
Asteroids are large chunks of rocky material with some metals in it. There is large group of
asteroids orbiting the sun between the orbits of Mars and Jupiter. This is called the asteroid
belt. Most of the asteroids in our solar system are found there. They orbit the sun just as the
planets do. They are too small to be planets. Astronomers think that the asteroid belt is made
up of material that was never able to form into a planet, or it could be parts of a planet that
broke apart long ago. The asteroid belt contains millions of asteroids. The largest asteroid is
about one-fourth the size of our moon.
Claim
After
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3. Comets travel
between 0 and 2,000
miles per hour.
Agree
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4. A comet is made of
rock, dust, and gases
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8. A shooting star
occurs when a star burns
out while traveling across
the night sky
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9. Most meteoroids
freeze before reaching
Earth.
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5. Asteroids revolve
around the Sun between
the orbits of Earth and
Mars
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Disagree
Directions: Use the article, Comets, Meteors, & Asteroids The Smaller Bodies in Our Solar System to fill in
the missing information in the cart below. Then, answer the questions.
Origin
Size
Comets
Kuiper Belt and Oort
Cloud
Asteroids
c.
Composition d.
Orbit
f.
Meteoroids
a.
b.
Rock
e.
g.
2. How does a comets appearance change as it approaches the sun? Why does this occur?
Sun
88 days
Thin atmosphere
Hydrogen
Helium
Interesting Fact #2
0
0
Rocky crust
Resembles the moon
Ancient lava flows
Mile-high cliffs
Moons
Rings
Venus
6.0 Light-min
2nd Planet From the sun
464C
12,104 km
Earth
8.3 Light-min
3rd Planet From the sun
-13C37C
12,756 km
24Hrs
0
0
78% Nitrogen
21% Oxygen
1% Traces of other
gases
Thick/toxic/dense
Rains Sulfuric acid
Carbon Dioxide
Nitrogen
Sulfur Dioxide
Carbon Monoxide
Argon
Flat angular rocks
Volcanoes
Mountains
Valleys
Hottest planet
1
0
Saturn
1.3 Light-Hours
6th Planet From the sun
-140C
120,536 km
Uranus
2.7 Light-Hours
7th Planet From the sun
-195C
51,118 km
4
8
4
10 hours 42 min
17 hours 12 min
No energy source
13% Helium (He)
85% Hydrogen (H) in thin
upper atmosphere
H2O & Methane
No solid surface
Interesting Fact #2
No solid surface
Hydrogen (H)
Helium (He)
Ammonia (NH3)
Methane (CH4)
Other toxic compounds
No solid surface
Moons
Rings
Directions: Use the Planet Comparison Charts on the other side to answer the questions.
1. List the planets from LARGEST to smallest. *use the diameter* (1-largest, 8-smallest)
1. ____________________ 2. ____________________ 3. ____________________
5. ____________________ 6. ____________________ 7. ____________________
4. ____________________
8. ____________________
2. List the planets in order from closest to the sun to farthest from the sun (1-closest, 8-farthest)
1. ____________________ 2. ____________________ 3. ____________________ 4. ____________________
5. ____________________ 6. ____________________ 7. ____________________ 8. ____________________
3. List the planets from hottest to coldest (1-hottest, 8-coldest)
1. ____________________ 2. ____________________ 3. ____________________
5. ____________________ 6. ____________________ 7. ____________________
4. ____________________
8. ____________________
4. List the planets from longest day to shortest day (1-longest day, 8-shortest day)
1. ____________________ 2. ____________________ 3. ____________________
5. ____________________ 6. ____________________ 7. ____________________
4. ____________________
8. ____________________
5. List the planets from longest year to shortest year (1-longest year, 8-shortest year)
1. ____________________ 2. ____________________ 3. ____________________
5. ____________________ 6. ____________________ 7. ____________________
4. ____________________
8. ____________________
6. List the planets from most moons to least moons (1-most moonds, 8-least moons)
1. ____________________ 2. ____________________ 3. ____________________
5. ____________________ 6. ____________________ 7. ____________________
4. ____________________
8. ____________________
Terrestrial Planets
Gas Giants