How the solar system formed

Grade 9 Science Worksheet - Building Confidence

Circle the best answer.

1. 1.

   a cloud, a spinning disk, young planets, today's solar system. How did the solar system begin, by Ari's reading (NASA)?

   • It formed during the first few minutes after the Big Bang began
   • A planet broke apart into pieces
   • The Sun spun off the planets later
   • A cloud of gas and dust collapsed under its own gravity
2. 2.

   Timeline ruler in billions of years. About when did the solar system form, by Bo's reading (NASA)?

   • About 4,600 years ago
   • About 4.6 billion years ago
   • About 13.8 billion years ago, with the universe
   • About 4.6 million years ago
3. 3.

   What formed first at the center of the collapsing cloud, by Kira's reading (NASA)?

   • Jupiter, the biggest planet
   • Earth, the first planet
   • The Sun, from most of the material
   • The asteroid belt
4. 4.

   “then” Why did the collapsing cloud flatten into a disk, by Jun's reading (NASA)?

   • It spun faster as it shrank and flattened
   • It stopped spinning and spread out
   • Wind from Earth pushed it flat
   • It cooled into a flat sheet of rock
5. 5.

   Why do all eight planets orbit in nearly the same flat plane, by Luz's reading?

   • They formed from one flat, spinning disk
   • The cloud did not spin
   • They broke off a larger planet
   • They were captured one at a time from space
6. 6.

   Orbit diagram with the disk's spin direction marked. In which direction do the planets orbit the Sun, by Milo's reading?

   • All the same way, the way the disk spun
   • They do not orbit; the Sun circles them
   • Inner one way, outer the other
   • Each in a random direction
7. 7.

   Which planets are rocky terrestrial planets, by Noah's reading (NASA)?

   • Saturn and Uranus
   • Earth and Jupiter
   • Jupiter, Saturn, Uranus and Neptune
   • Mercury, Venus, Earth and Mars
8. 8.

   What are asteroids, by Tala's reading (NASA)?

   • Rocky leftovers from the solar system's formation
   • Pieces of a planet that blew apart
   • Rocks thrown out by Earth's volcanoes
   • Pieces formed in just the last few thousand years or so
9. 9.

   Sun, inner planets, Jupiter and an asteroid belt. Where are most asteroids found, by Zee's reading (NASA)?

   • Where a lost planet broke up
   • Between Earth and the Moon
   • Inside Mercury's orbit
   • Between Mars and Jupiter
10. 10.

    Orbit diagram with the Kuiper Belt beyond Neptune. What does NASA say the icy worlds of the Kuiper Belt, beyond Neptune, are, by Esme's reading?

    • Rocky planets like Earth
    • New worlds forming today
    • Pieces broken off Neptune
    • Icy leftovers from the solar system's formation