Earth Science

Earth in Space

Surface Features of the Sun

Study Tip
Remember the acronym SSS—Sunspots, Solar Flares, Solar Prominences—as the surface features of the sun.

Sunspots

  • Sunspot: Cool, dark area on the Sun’s surface that have lower temperatures than surrounding areas.
  • Located where loops of the Sun’s magnetic field break through the surface.
  • Sunspots usually occur in pairs. They also appear in 11-year cycles.
Study Tip
Remember the acronym SSS—Sunspots, Solar Flares, Solar Prominences—as the surface features of the sun.
  • Smooth transfer of heat from lower layers of the Sun is disrupted. Sunspots are therefore cooler, darker, and marked by intense magnetic activity.
  • When loop of Sun’s magnetic field breaks through the surface, a sunspot is created where the loop comes out and where it goes back in again.

Solar Flares

  • Solar Flare: A violent explosion on the Sun’s surface.
  • Loop of the sun's magnetic field snaps and breaks.
  • Strong solar flares can turn into a coronal mass ejection. These release highly energetic particles that make up solar wind.
  • Solar wind sends out large amounts of harmful radiation.
Solar Flares
(a) Sunspots (b) A close-up of a sunspot taken in ultraviolet light

Solar Prominences

  • Solar Prominence: Plasma loop flowing between sunspots.
  • Plasma flows along a loop of the Sun’s magnetic field from sunspot to sunspot. Forms a glowing arch that reaches thousands of kilometers into the Sun’s atmosphere.
  • Can last lengths of time ranging from a day to several months.
  • Visible during a total solar eclipse.
Solar Prominences
Concept Check
  • What are sunspots? Why do you see them in pairs?
  • What are solar flares? How are they related to solar winds?
  • What are solar prominences?