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K12 LibreTexts

22.1: Sun

  • Page ID
    6144
  • How can we learn about something as hot as the Sun?

    Humans have sent spacecraft up to study our star. The SOHO spacecraft has been in operation since 1996. The craft orbits the Sun in step with Earth but closer to it. SOHO has sent back amazing images. Onboard instruments have also sent back mountains of data. The data is mostly about the Sun's outer layers.

    The Sun

    Our Sun is a star, a sphere of plasma held together by gravity. It is an ordinary star that is extraordinarily important. The Sun provides light and heat to our planet. This star supports almost all life on Earth.

    The Sun is the center of the solar system, which includes all of the planets and other bodies that orbit it. It is by far the largest part of the solar system (Figure below). Added together, all of the planets make up just 0.2 percent of the solar system's mass. The Sun makes up the remaining 99.8 percent of all the mass in the solar system!

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    The sizes of the planets relative to the Sun, if the Sun were the size of a basketball.

    Summary

    • The Sun is an ordinary star. It supports nearly all life on Earth.
    • The Sun is at the center of the solar system.
    • The Sun makes up almost all of the mass of the solar system.

    Review

    1. What are the major properties of the Sun?
    2. Where is the Sun located?
    3. Why is the Sun important to life on Earth?

    Explore More

    Use the resource below to answer the questions that follow.

    1. Why is it that you can't see the star closest to Earth in the night sky?
    2. Where is the Sun located?
    3. Why is our Sun special? Is it a special type of star?
    4. What is the structure of the solar system from the center to the farthest reaches?
    5. Which type of solar system bodies come from the farthest part of the solar system?