Planets and Moons

5 questions to test your knowledge of the outer solar system

What is the name of the region past the orbit of Neptune, that’s full of dwarf planets like Pluto and other small, icy bodies?

A. The Oort Cloud

B. The Kuiper Belt

C. The Frozen Zone

D. The Ice Line

B. The region of small icy bodies beyond the orbit of Neptune is called the Kuiper Belt.


Which of these outer solar system moons DOESN’T have an internal ocean?

A. Pan

B. Titan

C. Ganymede

D. Enceladus

A. Pan. Pan is a small, rocky, ravioli-shaped moon of Saturn, formed from material in Saturn’s rings.

How many Earths could fit inside Jupiter’s Great Red Spot?

A. 15

B. 100

C. 3

D. 1

D. Only 1 Earth can fit inside Jupiter’s Great Red Spot. When it was first discovered in the 1600s, the GRB was so big it could have fit 3 Earths. In the last few decades, scientists have noticed that the massive storm is shrinking.

What’s unusual about Uranus’s rotation?

A. It rotates in the opposite direction as the other planets

B. It rotates on its side

C. It rotates extremely slowly

D. It rotates extremely fast

B. It rotates on its side. Uranus’s axis is tilted 98 degrees (to compare, Earth’s is tilted 23 degrees) which means it’s “lying” on its side compared to the other planets in the solar system.

Which is closer to the Sun, Neptune or Pluto?

A. Neptune

B. Pluto

C. It’s complicated

C. It’s complicated. For 20 out of its 248-year orbit around the Sun, Pluto travels inside of Neptune’s orbit. This is because Pluto’s orbit is more of a stretched out oval than Neptune’s.