Stars similar to our Sun — “solar proxies” — enable scientists to
look through a window in time to see the harsh conditions prevailing in
the early or future Solar System, as well as in planetary systems around
other stars. These studies could lead to profound insights into the
origin of life on Earth and reveal how likely (or unlikely) the rise of
life is elsewhere in the cosmos. This work has revealed that the Sun
rotated more than ten times faster in its youth (over four billion years
ago) than today generating a stronger magnetic field and stronger
activity. This also meant that the young Sun emitted X-rays and
ultraviolet radiation up to several hundred times stronger than the Sun
does today.
Source and full zoom image -
http://www.iau.org/public/images/detail/iau0916a/
Credit: IAU/E. Guinan
