How the solar system formed

Grade 9 Science Worksheet - Challenge Me

Circle the best answer.

1. 1.

   Drawing of a young star with a flat dusty disk around it. A young star is seen with a flat, spinning disk of gas and dust around it. What does the formation model predict, by Esme's reading?

   • The disk will turn into a second star
   • Nothing; disks do not form planets
   • Giants close in, rocky planets farther out
   • Planets may form: rocky ones close in, giants farther out
2. 2.

   Luz's friend says the solar system formed in the Big Bang. Which response is best?

   • Agree: the Sun and planets are 13.8 billion years old, the universe's age
   • Agree: everything formed at once
   • Disagree: it formed a few thousand years ago
   • Disagree: it formed about 9 billion years after the universe began
3. 3.

   Milo's cousin says the asteroid belt is a planet that exploded. Which response is best (NASA)?

   • Agree: Jupiter's gravity smashed a planet that once orbited there
   • Disagree: it is material that never formed a planet
   • Disagree: it is gas, not rock
   • Agree: a planet broke apart there
4. 4.

   Disk with a hot inner zone and a cold outer zone. Noah's friend says Jupiter is a gas giant because it formed closest to the Sun's heat. Which response is best?

   • Agree: the Sun puffed it up with gas
   • Disagree: Jupiter is a rocky planet
   • Disagree: it formed far out, where ices and gases could gather
   • Agree: heat makes gas planets
5. 5.

   4.6 billion years = 24 hours. If the solar system's 4.6 billion years were one 24-hour day, about how long would 1 million years last, by Pia's math?

   • About 1 minute
   • About 19 seconds
   • About 19 hours
   • About 0.19 seconds
6. 6.

   4.6 billion years = 24 hours; universe about 13.8 billion years. On that same 24-hour day, how many hours ago did the universe begin, about 13.8 billion years before today, by Ren's math?

   • About 72 hours ago
   • About 24 hours ago, at the same moment
   • About 13.8 hours ago
   • About 8 hours ago
7. 7.

   Meteorite samples and asteroids are dated to about 4.6 billion years. Earth's surface rocks are mostly much younger. Why, by Tala's reading?

   • Asteroids are pieces of an older planet
   • Earth's surface keeps changing, but leftovers have not
   • Earth formed long after the asteroids
   • The dates mean the solar system is young and still forming
8. 8.

   Thousands of planetary systems are now known (NASA). Why do astronomers compare them with our solar system, by Zee's reading?

   • To find planets that broke apart into asteroid belts like ours
   • Because they formed in the Big Bang
   • To show each system matches ours exactly
   • To test whether the formation model works for other stars
9. 9.

   Comets from the far outer solar system are rich in ice. Why does that fit the model, by Ari's reading?

   • Comets formed recently from Earth's water
   • Comets broke off Earth's oceans
   • Ice formed near the hot Sun
   • Ice survived in the cold outer disk, where they formed
10. 10.

    Four evidence cards, labeled A to D. Which evidence best supports a spinning disk origin, by Bo's reading?

    • The planets have different colors
    • Planets orbit in nearly one plane, in one direction
    • Rocky planets are found farthest from the Sun, and giants closest
    • The asteroid belt is a broken planet