Download The Gas Giant Planets

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Date
The Gas Giant Planets
By Patti Hutchison
Caption: Picture of Saturn from the Hubble Space Telescope
Jupiter, Saturn, Uranus, Neptune. These are the giant gas planets.
Scientists think they are made of small, solid cores. Their interiors are
fluid. Lightweight gases such as hydrogen and helium make up most
of their mass. With all their satellites and ring systems, they are very
interesting to observe.
Jupiter is the largest planet. It is the fifth from the sun. The length
of its year is about 4330 Earth days. This is how long it takes for Jupiter to make one revolution around the sun.
It spins very fast, however. It takes only about nine Earth hours for Jupiter to make one rotation.
Jupiter's diameter is eleven times larger than Earth's. In fact, Jupiter is only ten times smaller than the sun.
This giant planet makes up about 70 percent of all the planetary matter in our solar system.
Jupiter's atmosphere is made of mostly helium and hydrogen. There are strong winds in its upper atmosphere.
These cause violent storms that rage almost all the time. The Great Red Spot is actually a giant storm. It has
been seen for over 300 years.
Other interesting features of Jupiter are its moons and ring. Jupiter has 62 moons. Some are almost as big as
planets. One moon, called Io, is the most volcanically active body in the solar system. Jupiter also has a ring
made mostly of dust particles. It is 6400 kilometers wide.
Saturn is the first planet known to have rings. The rings exist in a system. These rings are made of pieces of
rock and ice. Scientists believe these particles came from shattered comets, asteroids, or moons. The particle
sizes range from microscopic to as large as a house. Saturn has thousands of rings that are the largest and
brightest in the solar system. In addition to the rings, Saturn has at least 48 moons orbiting it.
Saturn's orbit takes over 29 Earth years to complete. Like Jupiter, however, it spins quickly in space. It takes
a little over 10 hours to complete one rotation. Also like Jupiter, Saturn's atmosphere is made of mostly hydrogen
and helium. It has violent winds, blowing at over 1100 miles per hour at the equator.
Uranus is the seventh planet from the sun. Its year is equal to 84 Earth years. Uranus is very large and made of
gas. It has no solid surface. Its atmosphere is made up of helium and hydrogen. It also contains methane, which
gives it its bluish color. Seasons last over 20 years on Uranus. Scientists believe this is because it is tipped on its
side. Like the other gas planets, it has eleven rings, and it has 27 moons.
About 60 Earths could fit inside Neptune, the fourth largest planet in the solar system. Scientists believe it is
the windiest planet. Winds blow at over 1200 miles per hour. Large storms rage above the planet. Once,
Neptune had a Great Dark Spot as big as Earth. It was a storm that blew across the surface at over 700 miles per
hour. It has disappeared, but a new spot is now visible.
It takes Neptune 165 Earth years to complete one orbit around the sun. It takes 16 Earth hours to make one
rotation. This gas giant has six rings and 13 known moons. One of its moons, Triton, orbits backward. Nitrogen
geysers have been observed on Triton.
Studying the giant gas planets helps us to learn much about the solar system. We can study how the solar
system was before the planets formed. Some of these planets' moons show us what the atmosphere was like on
Earth before life began. Many questions can be answered.
Name
Date
The Gas Giant Planets
Questions
1. What is the largest planet?
A. Saturn
B. Jupiter
C. Uranus
2. What is the Great Red Spot on Jupiter?
A. a crater
B. a nitrogen geyser
C. a giant storm
3. What are Saturn's rings made of?
4. How many Earth years does it take Saturn to complete one orbit around the sun?
A. 29
B. 4330
C. 70
5. What gas gives Uranus a bluish color?
A. hydrogen
B. oxygen
C. methane
6. What was Neptune's Great Dark Spot?
Write a paragraph comparing the lengths of the orbits of all the gas giant planets.
Name
Date
If you could study one of the gas giant planets up close, which one would you choose? Tell why you chose this
one.