The large concentration of stars that fills the middle of
this image is the open cluster known as M 35. Within an area
of the sky the size of the full moon, M 35 contains several
hundred stars. In a clear, dark sky, M 35 is visible to the
unaided eye as a fuzzy patch near the foot of the constellation
Gemini. It is 2800 light years from earth, 24 light years in
diameter, and 95 million years young.

More than 5 times farther away from earth is the compact open
cluster that is on the left edge of this image, NGC 2158. This
cluster is one of the oldest known, over a billion years old. Most
star clusters scatter long before this, but NGC 2158 is located
near the edge of the galaxy and is more tightly packed than most
clusters. Perhaps its internal gravity, and its life far from most
of the disrupting influences of the rest of the galaxy, has helped
it hold together so long.

Image data:
Camera: Canon 350 XT (modified)
Exposure: ISO 800, 5 minutes x 17
Telescope: 10" Schmidt-Newtonian, Baader coma corrector