Explanation:
Why would a small part of the Sun appear slightly dark?
Visible above is a close-up picture of a
sunspot, a depression on the Sun's face that is slightly cooler and less luminous than the rest of the
Sun.
The Sun's complex
magnetic field creates this cool region by inhibiting hot material from entering the
spot.
Sunspots can be larger than the Earth
and typically last for only a few days.
This high-resolution picture also shows clearly that the
Sun's face is a bubbling sea of separate cells of
hot gas.
These cells are known as granules.
A solar granule is about 1000
kilometers across and lasts about 10 minutes. After that, many
granules end up exploding.
