September

Peering upward on late September evenings, the sky is dominated by the Milky Way, which arches from the southwest to the northeast.  High overhead, we can easily view the Great Rift, an area within the Milky Way but, seemingly, almost completely devoid of stars.  In fact, this absence of stars is due to the gas and dust, common in spiral galaxies such as our own, which obscures the stars beyond.

NASA/JPL-Caltech/ESO/R. Hurt

Now is a great time to gaze into our dark skies and to contemplate the Milky Way, our home galaxy.   After twilight ends on late September evenings, the luminous band of the Milky Way stretches from the southwest to overhead and beyond, into the northeastern sky.   To the southwest in the direction of Sagittarius, the Milky Way’s clouds of stars and glowing gas are brightest.  This is the direction of the galactic center, where stars are most concentrated.   As we trace the Milky Way from overhead in Cygnus and into Perseus in the no