M51: Cosmic Whirlpool
Follow the handle of
the
Big Dipper away from the dipper's bowl, until
you get to the handle's last bright star.
Then, just slide your telescope a little
south and west and you
might find this
stunning
pair of interacting galaxies,
the 51st entry
in Charles Messier's famous catalog.
Perhaps the
original
spiral nebula, the large galaxy with
well defined spiral structure is also cataloged as NGC 5194.
Its spiral arms and dust lanes clearly sweep in front of
its companion galaxy (right),
NGC 5195.
The pair are
about 31 million light-years distant and
officially lie within the boundaries of the small constellation
Canes Venatici.
Though M51
looks faint and fuzzy in small, earthbound telescopes,
this sharpest
ever picture of M51 was made in January 2005 with the
Advanced Camera for Surveys on board
the Hubble Space Telescope.