The Sun's life from start to finish

Grade 9 Science Worksheet - Challenge Me

Circle the best answer.

1. 1.

   NASA says some massive stars live only a few million years, while the Sun gets about 10 billion. Why, by Jun's reading?

   • Massive stars use fuel more slowly but have less
   • Massive stars use their fuel much faster
   • Small stars use fuel faster than big ones
   • Massive stars burn with more oxygen
2. 2.

   NASA says some low-mass stars will shine for trillions of years. Why, by Kira's reading?

   • They use their fuel very slowly
   • They are white dwarfs still fusing slowly
   • They will explode before long
   • They use fuel quickly but have far more
3. 3.

   Low mass to white dwarf, high mass to supernova. Milo's cousin says the Sun will end in a supernova. Which response is best?

   • Disagree: it will become a black hole
   • Disagree: it lacks the mass; it will end as a white dwarf
   • Agree: stars like the Sun end that way, after the red giant stage
   • Agree: red giants explode
4. 4.

   Star card cutaway of a white dwarf with heat arrows leaving it. Noah's friend says a white dwarf is just a small star still fusing hydrogen. Which response is best?

   • Disagree: fusion has stopped; it glows from leftover heat
   • Disagree: it fuses iron in its core
   • Agree: it is a protostar
   • Agree: stars keep fusing hydrogen until they slowly fade away
5. 5.

   If the Sun's 10-billion-year main sequence were a 100-year life, about how old would the Sun be now, by Pia's math?

   • About 96 years, nearly done
   • About 4.6 years
   • About 46 years old
   • About 10 years
6. 6.

   Compare the Sun's main-sequence time already passed (4.6 billion years) with the time left (about 5.4 billion). Which is true, by Ren's math?

   • Most of it has already passed
   • Almost nothing of it is left
   • A little more time is ahead than has passed
   • Exactly half is left, to the year
7. 7.

   Earth is about 4.5 billion years old (USGS), and the Sun about 4.6 billion (NASA). What does this suggest, by Tala's reading?

   • They formed at about the same time from the same cloud
   • Earth formed long after the Sun's life ended
   • The Sun formed in the last few thousand years
   • Earth formed billions of years before the Sun did, in another cloud
8. 8.

   No one can watch a star for 10 billion years. How do astronomers know what the Sun will become, by Zee's reading (NASA)?

   • They watched one star pass through each stage
   • They guess, with no evidence
   • They watched an earlier sun go through its whole life and end
   • They observe many stars at different stages of life
9. 9.

   Drawing of a ring-shaped glowing cloud with a small hot star at its center. NASA describes the Helix Nebula, 650 light-years away, as a planetary nebula. What does it show about the Sun's future, by Ari's reading?

   • A picture of the Sun's own past
   • A Sun-like star's shed layers around a white dwarf
   • A cloud where a Sun-like star is being born
   • The leftovers of a supernova
10. 10.

    Drawing of a dark cloud of gas and dust with young stars glowing inside it. NASA says the Sun formed in a collapsing cloud of gas and dust. Which evidence fits, by Bo's reading?

    • Stars form just from supernova cores
    • Stars form inside white dwarfs
    • No stars are forming anywhere now
    • Stars are seen forming today inside clouds of gas and dust