The Sun's life from start to finish

Grade 9 Science Worksheet - Challenge Me

Circle the best answer.

1. 1.

   Low mass and high mass. A star has the same mass as the Sun. Which ending fits it, by Esme's reading?

   • Supernova, then a neutron star
   • It goes dark once its core hydrogen is used up
   • Red giant, planetary nebula, then white dwarf
   • Straight to a white dwarf with no giant stage
2. 2.

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

   • Small stars use fuel faster than big ones
   • Massive stars burn with more oxygen
   • Massive stars use fuel more slowly but have less
   • Massive stars use their fuel much faster
3. 3.

   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 use fuel quickly but have far more
   • They will explode before long
4. 4.

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

   • Agree: red giants explode
   • Agree: stars like the Sun end that way, after the red giant stage
   • Disagree: it will become a black hole
   • Disagree: it lacks the mass; it will end as a white dwarf
5. 5.

   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: it fuses iron in its core
   • Agree: it is a protostar
   • Disagree: fusion has stopped; it glows from leftover heat
   • Agree: stars keep fusing hydrogen until they slowly fade away
6. 6.

   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 46 years old
   • About 96 years, nearly done
   • About 4.6 years
   • About 10 years
7. 7.

   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?

   • Exactly half is left, to the year
   • Almost nothing of it is left
   • Most of it has already passed
   • A little more time is ahead than has passed
8. 8.

   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?

   • The Sun formed in the last few thousand years
   • They formed at about the same time from the same cloud
   • Earth formed billions of years before the Sun did, in another cloud
   • Earth formed long after the Sun's life ended
9. 9.

   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 observe many stars at different stages of life
   • They watched an earlier sun go through its whole life and end
   • They guess, with no evidence
10. 10.

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