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?

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

   If a cloud collapsed without spinning, what would the model predict, by Jun's reading?

   • The same flat, spinning disk as before, with the same planets
   • No flat disk, so no neat set of orbiting planets
   • Planets older than the star
   • Giants close to the star
3. 3.

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

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

   • Disagree: Jupiter is a rocky planet
   • Agree: the Sun puffed it up with gas
   • 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 19 seconds
   • About 0.19 seconds
   • About 19 hours
   • About 1 minute
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 24 hours ago, at the same moment
   • About 8 hours ago
   • About 13.8 hours ago
   • About 72 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?

   • Earth formed long after the asteroids
   • The dates mean the solar system is young and still forming
   • Asteroids are pieces of an older planet
   • 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 show each system matches ours exactly
   • To find planets that broke apart into asteroid belts like ours
   • Because they formed in the Big Bang
   • 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
   • Ice survived in the cold outer disk, where they formed
   • Ice formed near the hot Sun
   • Comets broke off Earth's oceans
10. 10.

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

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