If you're a Northern Hemisphere observer, you'll notice that at this time of year, the Milky Way isn't visible. In fact, during late-spring evenings the Milky Way roughly circles the horizon -- almost impossible to see even on a dark night -- which means the sky overhead, or close to it, is as far from the Milky Way as possible.

You may remember that the Milky Way Galaxy roughly resembles a flattened disk, much thinner than it is broad. Like most stars, the Sun stays within this disk. When you look in or near the plane of the disk, you see enormous numbers of stars, but when you look straight out of the disk -- towards the "galactic poles" -- the sky looks relatively empty.

The view there may be empty of nearby stars and nebulas, but not of objects outside the Milky Way. With fewer stars, nebulas, and other galactic material to interfere, external galaxies are much easier to see. By a curious coincidence, a very rich collection of galaxies -- the Virgo Cluster, named after the constellation most of them appear in -- exists right near the north galactic pole. More below...