Skywatch Line for Wednesday and Thursday, January 15 and 16, 2025, written by Alan French

This is Dudley Observatory’s Skywatch Line for Wednesday and Thursday, January 15 and 16, 2025, written by Alan French.

The Sun rises at 7:23 A.M. on Wednesday and sets at 4:47 P.M. On Thursday it rises at 7:22 A.M. and sets at 4:48 P.M. Thursday gained 10 minutes, 50 seconds of daylight compared to last Thursday.

The Moon was full last Monday and is now moving toward last quarter. On Wednesday, the waning gibbous Moon, 95% sunlit, will rise at 6:44 P.M. in the east northeast. By 9 P.M. it will be 22 ½ degrees above the eastern horizon. The Moon will rise at 7:52 P.M. on Thursday, appearing 90% sunlit and will be 11 degrees high in the east by 9 P.M. The Moon will reach last quarter next Tuesday.

Saturn, at magnitude +1.1, 200 times fainter than Venus, is now quite close to Venus. On Wednesday at 7:00 P.M. Saturn will be 3 ¼-degrees to the upper left of Saturn. A7 7:00 on Thursday they will be just under 3-degrees apart. They will be closest on Friday.

The Internation Space Station (ISS) will be visible both nights. On the two nights it will be high in the sky and reach magnitude -3.7 when highest. Venus, by comparison, is brighter at magnitude -4.5.

On Wednesday the ISS pass will occur after most of the evening twilight is gone and the skies are dark. Look for the space station in the west southwest at 6:13 P.M. At first it is moving slowly and not very bright, so it may be hard to spot. Just after 6:14 it will be as high as Venus but about 15-degrees north of the planet. By 6:15 it will be moving through Pegasus. After passing through the northwest corner of the Great Square of Pegasus, it will be moving toward the familiar “W” pattern of stars marking Cassiopeia. It will begin moving through the “W” around 18:16:30 (HH:MM:SS) and then head down toward the northeastern horizon. When well above the horizon it will move into the Earth’s shadow and fade from view.

The ISS pass on Thursday will be earlier, when the skies are still bright with evening twilight. Look for the station at 5:25 P.M. low in the southwest. At 5:26 P.M. it will be approaching Venus and will pass just north of the planet at 5:26:30. The path of the ISS will continue across the south to southeast sky, passing between Jupiter and Capella as it moves toward the northeast. Just after 5:30 it will pass close to Castor and then just north of Pollux and Mars before moving into the Earth’s shadow when approaching the horizon.