“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. Field trip requests are
welcome. NOTE: field trip request form for Fall 2022 is now live, and the schedule of free public shows
has been posted.
Fall begins this week on Thursday, September 22, at 9:04 p.m. Eastern Daylight Time (in Universal Time,
that’s 01:04 on the 23 rd ). This is the moment the sun crosses the celestial equator, as it goes from the
northern half of the sky to the southern half. We see it rise due east and set due west; the fall and spring equinoxes are the only dates on which it does this. The days are now getting shorter at their fastest rate of the year, over two and a half minutes of daylight lost each day. As the weeks go by, this pace will slow until the days begin to grow longer once again after December 21.
The New Moon also occurs this month, on September 25. For a challenge, try to spot the very thin crescent moon as close as you can to the new moon. The Old Moon, as it’s sometimes called, appears in the east just before sunrise, and the Young Moon appears in the west after sunset. Consult the
accompanying images for a guide.
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.