From the Earth, our Milky Way Galaxy is visible as a milky band that stretches across the night sky. It is easier to see when you are far from bright city lights.

To reach the center of the Milky Way Galaxy starting from the Earth, aim toward the constellation Sagittarius. If you were in a spacecraft, during the trip you would pass the stars in Sagittarius one by one (and many other stars!).

Since we're inside the Milky Way Galaxy and we've never sent a spacecraft outside our Galaxy, we have no photographs of the Milky Way Galaxy. Radio telescope data does, however, let us know a lot about it.

The arms of the Milky Way are named for the constellations that are seen in those directions. The major arms of the Milky Way galaxy are the Perseus Arm, Sagittarius Arm, Centaurus Arm, and Cygnus Arm; our Solar System is in a minor arm called the Orion Spur. The central hub (or central bulge) contains old stars and at least one black hole; younger stars are in the arms, along with dust and gas that form new stars.

The great rift is a series of dark, obscuring dust clouds in the Milky Way. These clouds stretch from the constellation Sagittarius to the constellation Cygnus.

The Milky way Galaxy is just one galaxy in a group of galaxies called the Local Group. Within the Local Group, the Milky Way Galaxy is moving about 300 km/sec (towards the constellation Virgo). The Milky Way Galaxy is moving in concert with the other galaxies in the Local Group (the Local Group is defined as those nearby galaxies that are moving in concert with each other, independent of the "Hubble flow" expansion).

Harlow Shapley (November 2, 1885- October 20, 1972), an American astronomer, was the first person to estimate the size of the Milky Way Galaxy, as well as our position in the galaxy (about 1918).

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Make a galaxy of stars from glitter or sand on black paper