Planets and other objects in the solar system

Grade 6 Science Worksheet

Circle the best answer.

1. 1.

   Object card: nearly round, orbits the Sun beyond Neptune, among many other icy bodies in its path. Which type of object is it, Ari?

   • A planet, as it is round and orbits the Sun
   • A moon, as it is small
   • A dwarf planet, like Pluto
   • A comet, as it is icy
2. 2.

   Object card: rocky, lumpy, about 530 km wide, orbits the Sun between Mars and Jupiter. Which type of object is it, Bo?

   • A comet
   • An asteroid
   • An ice giant
   • A moon of Mars
3. 3.

   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

4. Read this first

   Use this

   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.

5. 4.

   Using the outer-planet table, which planet has the most moons, Jun?

   • Neptune, with 16
   • Jupiter, the widest planet, with 95
   • Uranus, with 28
   • Saturn, with 274
6. 5.

   Luz wants to draw rings on the outer planets for a poster. Using the table, which of them have rings?

   • All four of them
   • Jupiter and Saturn
   • Uranus and Neptune
   • Just Saturn
7. 6.

   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 is not round
   • It fails no rule, so it is a planet
   • It has not cleared its orbit
   • It does not orbit the Sun
8. 7.

   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 planet, as it is round
   • It is a comet with a long tail
   • It is a moon of Mars
9. 8.

   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
10. 9.

    A comet takes less than 200 years to go around the Sun. Where did it most likely come from, Tala?

    • The Oort Cloud, far beyond
    • The asteroid belt
    • The Kuiper Belt, beyond Neptune
    • The inside of the Sun
11. 10.

    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