Sky watch: Galaxies of the springtime sky

This week, the moon and its obscuring light is nowhere during early evening hours, so it marks a great time to take a gander around a pristine rural sky. But beyond the stars lie other galaxies that populate the cosmos far beyond the reach of the human eye.

But that's pretty much it as far as galaxies go. That's as far as the human eye can see without help. Aim a small telescope skyward, however, and all that changes.

But in the region of the springtime sky between the Big Dipper, Coma Berenices and Virgo lies one of the richest regions of galaxies visible to backyard telescopes. It's called the Realm of the Galaxies, and it's definitely a sight.

Some night when you're far fromcity lights, scan your telescope slowly through this area. Even an instrument of 4 or 6 inches in diameter will reveal patch after patch of fuzzy light among the much-sharper stars -- dozens of individual galaxies whose light left their sources back when dinosaurs ruled the Earth.

In the constellation of Virgo, for example, we find the Virgo cluster of galaxies, a system of several thousand galaxies bound by gravitation some 60 or 70 million light years from the Milky Way. Though we see only the brightest as tiny fuzz balls of light, most are massive spiral and elliptically shaped structures.

Farther to the north -- in the constellation Coma Berenices, Berenice's Hair -- we find the Coma cluster. Lying some 400 million light years away, this cluster has a thousand galaxies embedded in a region filled with hot gas. As the galaxies move through this gas, they seem to become stripped of their own gas and dust, the raw materials out of which new stars and planetary systems are born.

So the next clear dark night, take your telescope out for a spin through the cosmos. You'll be able to visit not only stars throughout our Milky Way, but also dozens of other galaxies.