Life Cycle of Stars · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Life Cycle of Stars

Science · Space Exploration · ages 9-11
Name ______________________   Date ____________

  1. What do stars fuse together in their core to make energy?

    • Rock into lava
    • Hydrogen into helium
    • Water into steam

  2. Where do stars begin their life?

    • A nebula, a cloud of gas and dust
    • A black hole
    • Another star that already exists

  3. A star can shine steadily for millions or even billions of years.

    Circle one:   True   False

  4. A star has been shining brightly for 2 billion years without going out. What is powering it the whole time?

    • Fusing hydrogen into helium in its core
    • Burning like a campfire burns wood
    • Bouncing sunlight off nearby planets

  5. Which comes right before a star begins to shine?

    ?Shining starEnd
    • A black hole shrinking down
    • A comet breaking apart
    • A nebula pulled together by gravity

  6. Astronomers spot a giant star, twenty times as heavy as the Sun, near the end of its life. How will it most likely end?

    • By quietly shrinking into a white dwarf
    • In a huge explosion called a supernova
    • By turning back into a nebula

  7. Jake says, 'Every single star ends its life by exploding as a supernova.' What is wrong with what Jake said?

    • Only massive stars explode; smaller stars shrink into white dwarfs instead
    • Stars never end, they shine forever
    • Nothing, Jake is completely right

  8. Our Sun is a medium-sized star, not a massive one. Based on what you know, what will most likely happen when it dies?

    • It will explode as a supernova
    • It will turn back into a nebula exactly as it was before
    • It will shrink into a small white dwarf
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Answer key

For grown-ups. Fold this page away before handing over the rest.

Life Cycle of Stars W1-mt_iTjrKEdAOj-s1

  1. Hydrogen into helium · Deep in a star's core, hydrogen atoms fuse into helium, releasing energy that makes the star shine.
  2. A nebula, a cloud of gas and dust · Stars start inside nebulae, huge clouds of gas and dust in space.
  3. True · Fusion releases energy slowly and steadily, so a star can keep shining for an extremely long time.
  4. Fusing hydrogen into helium in its core · Stars don't burn like fire. They shine because hydrogen keeps fusing into helium deep in the core.
  5. A nebula pulled together by gravity · Before a star shines, gravity pulls the gas and dust in a nebula together until the center gets hot enough.
  6. In a huge explosion called a supernova · The star is far more massive than the Sun, and only massive stars end in a huge explosion called a supernova.
  7. Only massive stars explode; smaller stars shrink into white dwarfs instead · Jake left out smaller stars. Only the biggest stars explode as a supernova; stars like the Sun become white dwarfs.
  8. It will shrink into a small white dwarf · Only massive stars end in a supernova. A medium-sized star like the Sun shrinks down into a white dwarf instead.
Worksheet · LightMySky