. # 20
The Whirlpool galaxy, M51, and a companion galaxy. Just like other major
galaxies, this galaxy consists of billions of stars.  Galaxies are the
biggest single object we know of, other than groups (low density) and
clusters (much higher density) of galaxies which are gravitationally
bound, clouds, superclusters, walls encompassing bubble voids, and, of
course, the Universe and whatever may be past that.  The Whirlpool is
almost 20 times farther than the Pinwheel galaxy, about 35 million
light-years.  Imagine: when you look at this image, the light that
struck my negative and copied to the computer is light that left the
galaxy over 35 million years ago.  The 2 bright objects are individual
galaxies; it's thought that the top one (NGC 5195) "sped" thru the
bottom one.  If you look close enough, you'll find that the bottom
spiral arm is distorted and points to the top one.


#20     from IMG0017.pcd, taken 04/01/94, f/6.3, ASA 100, 8min