Skywatch Line for Wednesday October 16 and Thursday October 17th, 2024 written by Alan French
The Sun rises at 7:10 A.M. on Wednesday and sets at 6:10 P.M. On Thursday it rises at 7:12 and sets at 6:09. This Thursday has 19 minutes, 40 seconds less daylight than last Thursday.
The Moon reached first quarter last Thursday and is moving toward full. On Wednesday a bright, gibbous Moon, almost fully sunlit, will be low in the east as the Sun sets. By 7:00 P.M. the Moon will be 13 degrees above the horizon. It will be due south and 56 degrees high at 23 minutes after midnight. The Moon will be full at 7:26 Thursday morning.
At sunset on Thursday the full Moon, the Hunter’s Moon, will be rising. At 7:00 P.M. it will be 8 degrees above the eastern horizon. Since the Moon was at perigee, its closest approach to Earth in its orbit, a little over 9 ½ hours before full, the Moon will appear a little larger than normal. This has come to be called a supermoon. The Moon will be south and highest at 1:18 A.M. Friday.
The bright Moon makes viewing conditions for Comet Tsuchinshan-ATLAS less than ideal, but the comet has been visible by eye in the west about 45 minutes after sunset. My wife and I saw it on Saturday night. We spotted the head, appearing as a fuzzy spot, by eye just after 7:00 P.M. and a little later my wife could see a nice tail. I could only see a little of the tail by eye but saw a longer tail in binoculars.
Look for the comet at 7:00 P.M. in the west southwest. On Wednesday it will be 21 degrees above the horizon 22 degrees to the upper right of brilliant Venus. (If you hold your hand at arm’s length and stretch the fingers apart, they will span 25 degrees from the tip of the thumb to the tip of the little finger.) It will be 13 degrees higher than it was Saturday and out of the brighter twilight glow. Its higher elevation also means its light passes through less of Earth’s atmosphere. Both factors should improve the view. Comets usually fade as they move away from the Sun, so it is best to catch the comet as soon as we have clear skies. If you continue watching as twilight fades, darker skies should yield a better view.
On Thursday the comet will be higher and a little farther south. It will be 23 degrees above the west southwestern sky and 23 degrees to the upper right of Venus. During the coming nights it will continue moving higher and toward the south. By Saturday the Moon will absent at 7:00 P.M. but will rise at 7:16, providing a brief, moonless window. On Sunday the sky will be moonless until 8:00 P.M., allowing views of the comet later after sunset when the night sky is free of any sign of evening twilight. Things will continue to improve in the following days, but the comet will likely continue to fade as it moves away from the Sun.