S8-GU2L5 - The Gas Giants

S8-GU2L5 - The Gas Giants

CORE CONCEPT

What do you think is one difference between a gas giant planet and Earth? 

Some of the differences include the distance from the sun, the size, composition, ring systems, many moons instead of just one, not solid rock. 

VOCABULARY

Jupiter is a giant!

What weather event on Earth does Jupiter's Great Red Spot look like? 

Jupiter's Great Red Spot looks like a hurricane or other cyclonic storm. 

What does the size of the storm tell you about the size of Jupiter?

Jupiter is very big compared to Earth. 

Giant distances

Why do astronomers use astronomical units instead of miles or kilometers when measuring distances in space?

• Distances in space are vast. Planets are millions or billions of kilometers apart. Because of this, it is easier to use larger units, such as astronomical units. 

How do you think a planet's distance from the sun affects the planet's surface temperature? 

• In general, the farther a planet is from the sun, the colder its surface temperature is. 

The gas giants

How do the gas giants differ from the Earth?

• The gas giants are much larger than Earth. They are composed mostly of hydrogen and helium, and they have planetary rings. 

Vocabulary:

Explain what a planetary ring is.

• A planetary ring is a thin ring of dust and other particles that surrounds a planet. 

Giant properties

Earth's day is 24 hours long. Earth's circumference is 40,074 kilometers (24,901 miles). That means that Earth rotates at about 1670 kilometers per hour (1038 miles per hour). Jupiter's day is 9 hours, 55 minutes long. Jupiter's circumference is 449,196 kilometers (279,118 miles). How fast is Jupiter rotating? 

• Jupiter's rotation is at least 45,282 kph (28,137 mph).

Which properties make these planets similar to each other and all very different from Earth?

• Distance from the sun, composition, rings, and number of moons are properties that makes these planets similar to each other and different from Earth. 

Compared to Earth

A trip to Jupiter could take anywhere from about 13 months to 6 years. If this were possible, what are some of the problems people would face inside their spacecraft? Would you want to make the trip? Why or why not?

• Think about some of the difficulties of extended space travel: air to breathe, water to drink, waste to dispose of, clean clothes to wear, getting exercise, and being with the same people for more than a year — or maybe for 6 years! 

How is Uranus's rotation different from Earth's?

• Uranus's axial tilt is more than 97 degrees, so it looks like Uranus was knocked on its side and is spinning on its side. Earth's rotation is the normal counterclockwise rotation (when viewed from above Earth’s North Pole.)

Characteristic properties

Describe a unique feature of each of the gas giants. 

• Jupiter has a large storm called the Giant Red Spot. Saturn has a vast ring system. Uranus's axis is tilted on its side. Neptune is 30 AU from the sun. 

List two ways that the gas giants are different from the terrestrial planets. 

• Unlike the terrestrial planets, the gas giants are composed mostly of gases. In addition, the gas giants are much larger than the terrestrial planets. 

What do you think?

How are the atmospheres of the gas giant planets different from the atmosphere of Earth?

• The atmospheres of the gas giants are mostly gas — hydrogen, helium, ammonia, and methane. None of those gases would support life. Also, the planets are so cold that some of the layers are liquid hydrogen or frozen ammonia, which would be a very hostile environment for humans. 

What two gases are the gas giants mostly composed of? 

• The two gases are helium and hydrogen.

Compare and contrast

Compare one of the gas giant planets to Earth.

• Here is the comparison for Jupiter: Jupiter is hundreds of times larger than Earth, made up mostly of gases instead of solids, has many more moons, has rings, is much colder, is much further from the sun, rotates on its axis faster, has a smaller axial tilt, and takes much longer to complete an orbit. 

How do you think the surface gravity of the gas giants relates to their masses?

• The gas giants with the largest masses have the greatest surface gravity. As mass decreases, so does surface gravity.

Summary

Lesson 5 Presentation

Complete