“The Sky This Week” appears every Tuesday. It is written by Ian Clarke, Director of the Hatter Planetarium at Gettysburg College. The planetarium offers regular educational presentations about the stars and the skies; there’s something for early elementary through adults. Public shows have concluded for the academic year, but we are still accepting field trip requests for the summer!
You may notice that the moon is not in the evening sky this week. It’s now a waning crescent, visible in the morning sky before sunrise until New Moon on July 17. A moonless summer night sky is a great time to look for the Milky Way, which appears as a band of faint light stretching from horizon to horizon. At 11 p.m., it goes from north-northeast, reaches its highest in the east as it goes through the Summer Triangle, and meets the horizon in the south. The Milky Way is our own galaxy, seen from the inside. All the stars we see are members of the Milky Way. We see the stars in our neighborhood as individuals, while the light of all the galaxy’s more distant members combines to form the Milky Way. Our Galaxy is a fairly flat disk about 90,000 light-years in diameter but only 1,000 light-years thick. That’s why it looks like a band around the sky rather than some other shape. We are located about two-thirds of the way from the center to the edge of the Milky Way.
Milky Way from Lubec, Maine, 2022. Photo by Ian Clarke.
Ian Clarke is the director of the Hatter Planetarium at Gettysburg College. In addition he has taught introductory astronomy labs and first-year writing there for over 30 years (not necessarily all at the same time). He was educated at Biglerville High School, the University of Virginia, and the University of Iowa. He lives in Gettysburg.
Ian, do you have suggestions for places with low light pollution in driving distance from Gettysburg?