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?

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

   • Massive stars use fuel more slowly but have less
   • Massive stars burn with more oxygen
   • Small stars use fuel faster than big ones
   • 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 use fuel quickly but have far more
   • They will explode before long
   • They are white dwarfs still fusing slowly
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: stars like the Sun end that way, after the red giant stage
   • Agree: red giants explode
   • 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: fusion has stopped; it glows from leftover heat
   • Disagree: it fuses iron in its core
   • Agree: stars keep fusing hydrogen until they slowly fade away
   • Agree: it is a protostar
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 96 years, nearly done
   • About 4.6 years
   • About 46 years old
   • 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?

   • A little more time is ahead than has passed
   • Most of it has already passed
   • Exactly half is left, to the year
   • Almost nothing of it is left
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 long after the Sun's life ended
   • Earth formed billions of years before the Sun did, in another cloud
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 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
   • They watched one star pass through each stage
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 Sun-like star's shed layers around a white dwarf
    • A cloud where a Sun-like star is being born
    • A picture of the Sun's own past
    • The leftovers of a supernova