Explanation:
Why are there dark spots on the sun?
Although noted for thousands of years,
sunspots
have been known for decades to be regions of the Sun that are
slightly depressed and cooled by the Sun's complex and changing
magnetic field.
High resolution pictures like the
above image from Japan's new Sun-watching
Hinode satellite,
however, are helping to increase modern understanding.
In the center of the
above image
is a sunspot, but not seen in the usual orientation --this
sunspot is seen sideways.
Of particular interest is
erupting glowing gas
that shows how the Sun's magnetic field comes
right out of the
spot center,
but curves markedly around the spot edges.
Better understanding of how the Sun ejects particles into space may result in more accurate predictions of
solar storms that affect satellites, astronauts, and even power grids on Earth.