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?

   • It goes dark once its core hydrogen is used up
   • Supernova, then a neutron star
   • Straight to a white dwarf with no giant stage
   • Red giant, planetary nebula, then white dwarf
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 burn with more oxygen
   • Massive stars use their fuel much faster
   • Small stars use fuel faster than big ones
   • Massive stars use fuel more slowly but have less
3. 3.

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

   • They use fuel quickly but have far more
   • They will explode before long
   • They are white dwarfs still fusing slowly
   • They use their fuel very slowly
4. 4.

   Luz's friend says the Sun will burn out soon, maybe within our lifetimes. Which response is best (NASA)?

   • Disagree: it has about 5 billion years of main-sequence life left
   • Disagree: the Sun will shine with no end
   • Agree: once its fuel dips, it will go dark at once
   • Agree: it is near the end of its fuel
5. 5.

   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
   • Agree: stars like the Sun end that way, after the red giant stage
   • Disagree: it lacks the mass; it will end as a white dwarf
   • Agree: red giants explode
6. 6.

   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?

   • Agree: stars keep fusing hydrogen until they slowly fade away
   • Disagree: fusion has stopped; it glows from leftover heat
   • Disagree: it fuses iron in its core
   • Agree: it is a protostar
7. 7.

   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 4.6 years
   • About 10 years
   • About 96 years, nearly done
   • About 46 years old
8. 8.

   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
   • Exactly half is left, to the year
   • Almost nothing of it is left
   • A little more time is ahead than has passed
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 one star pass through each stage
   • They watched an earlier sun go through its whole life and end
   • They observe many stars at different stages of life
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 inside white dwarfs
    • Stars form just from supernova cores
    • Stars are seen forming today inside clouds of gas and dust
    • No stars are forming anywhere now