Planets and other objects in the solar system
Grade 6 Science Worksheet

Circle the best answer.
Object card: rocky, lumpy, about 530 km wide, orbits the Sun between Mars and Jupiter. Which type of object is it, Bo?
- An ice giant
- An asteroid
- A comet
- A moon of Mars
Charon orbits Pluto and is so large it makes Pluto wobble. What kind of object is Charon, Esme?
- A moon of a dwarf planet
- An asteroid in the asteroid belt
- A planet, as it is so large
- A small star
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Data table (NASA Planetary Fact Sheet, 2025), columns Planet, Diameter (km), Moons and Rings. Jupiter: 142,984, 95, yes. Saturn: 120,536, 274, yes. Uranus: 51,118, 28, yes. Neptune: 49,528, 16, yes.
Using the outer-planet table, which planet has the most moons, Jun?
- Jupiter, the widest planet, with 95
- Neptune, with 16
- Saturn, with 274
- Uranus, with 28
Using the outer-planet table, how many more moons does Jupiter have than Uranus, Kira?
- 123
- 77
- 67
- 28
Luz wants to draw rings on the outer planets for a poster. Using the table, which of them have rings?
- Jupiter and Saturn
- All four of them
- Just Saturn
- Uranus and Neptune
The IAU says a planet must orbit the Sun, be mostly round, and clear its orbit of similar objects. Which rule does Pluto fail, Milo?
- It does not orbit the Sun
- It is not round
- It fails no rule, so it is a planet
- It has not cleared its orbit
Ceres is nearly round and orbits the Sun in the asteroid belt. Why is it a dwarf planet and not a planet, Noah?
- It shares its orbit with the asteroids around it
- It is a comet with a long tail
- It is a planet, as it is round
- It is a moon of Mars
Pia's NASA page lists the dwarf planets the IAU recognizes. Which is the one in the inner solar system?
- Earth's Moon
- Eris
- Pluto
- Ceres
A space probe heads for the main asteroid belt. Between which two planets' orbits does Ren expect to find it?
- Jupiter and Saturn
- Mars and Jupiter
- Earth and Mars
- Uranus and Neptune
Another comet can take millions of years to go around the Sun once. Where does it most likely come from, Zee?
- Saturn's rings
- The asteroid belt, near Mars
- Earth's Moon
- The Oort Cloud, far beyond the Kuiper Belt