“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.
Rising about an hour later each day as its illuminated portion grows, the moon advances through the waxing gibbous phase until it reaches full on October 9. On the night that it’s full, the moon will be quite close to the planet Jupiter. This closeness, however is just our line-of-sight perspective. The two objects may be only a few degrees apart in the sky, but the moon (372,000 km away) is in the foreground, while Jupiter (595,000,000 km away) is in the background.
Although the moonlight will be bright, keep an eye out for the bright star Capella, now rising in the northeast at 8:00 p.m., and well placed for viewing an hour or more later. You might notice that Capella’s light is slightly yellowish. Many, many stars are not simply white, but our eyes our only able to detect the color of the brighter ones. Though it appears to be a single star to our unaided eyes, Capella is in fact a system of four separate stars. Double and multiple star systems are common in the universe, especially among larger stars.
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.