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?

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

   A planetary system has a Jupiter-sized giant very close to its star. Why is this a puzzle for the simple model, by Kira's reading?

   • Giants are expected close in, so there is no puzzle
   • It shows the star formed after the planet
   • It must be a rocky planet
   • Giants should form far out, so it may have moved inward
3. 3.

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

   • Disagree: it formed a few thousand years ago
   • Agree: the Sun and planets are 13.8 billion years old, the universe's age
   • Agree: everything formed at once
   • Disagree: it formed about 9 billion years after the universe began
4. 4.

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

   • Agree: a planet broke apart there
   • Agree: Jupiter's gravity smashed a planet that once orbited there
   • Disagree: it is gas, not rock
   • Disagree: it is material that never formed a planet
5. 5.

   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?

   • Disagree: Jupiter is a rocky planet
   • Agree: heat makes gas planets
   • Agree: the Sun puffed it up with gas
   • Disagree: it formed far out, where ices and gases could gather
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 8 hours ago
   • About 24 hours ago, at the same moment
   • About 72 hours ago
   • About 13.8 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?

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

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

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

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

   • Ice formed near the hot Sun
   • Ice survived in the cold outer disk, where they formed
   • Comets broke off Earth's oceans
   • Comets formed recently from Earth's water
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
    • The asteroid belt is a broken planet
    • Planets orbit in nearly one plane, in one direction
    • Rocky planets are found farthest from the Sun, and giants closest