This is Dudley Observatory’s Skywatch Line for Wednesday and Thursday, January 31 and February 1, written by Alan French.
The Sun rises at 7:11 A.M. on Wednesday and sets at 5:06 P.M. On Thursday it rises at 7:10 and sets at 5:08. This Thursday ha 15 ¾ minutes more daylight than last Thursday. In January we gained just over
51 minutes of daylight. As the path of the Sun moves higher in our sky, the rate of increase accelerates. In February we will add just over 1 hour 16 minutes of daylight.
The Moon was full last Thursday and is moving toward last quarter. On Wednesday the Moon, 67% illuminated, rises at 11:05 P.M. It sets at 10:07 A.M. Thursday toward the west, appearing only 63% in sunlight. It
does not rise again until after midnight, appearing in the east at 12:09 A.M. Friday morning. The Moon will be 31 degrees above the southern horizon at 5:24 A.M. Friday morning and its visible face will be 55% in sunlight. The Moon will reach last quarter early Friday evening.
Jupiter is due south at 5:34 P.M. on Wednesday, during evening twilight. At an altitude of 60 degrees, it is well placed for observing with a telescope. The hours just after sunset sometimes feature steady skies
and some observers claim Jupiter’s colors stand out better against twilight skies. If you are interested in looking at Jupiter with a telescope, do it soon, before its highest appearance is lost to bright, daytime skies. On Thursday Jupiter is due south and highest at 5:31 P.M.
We have nice passes of the International Space Station (ISS) over Schenectady and the surrounding region on both nights. When high in the sky the ISS is brighter than any stars or planets as it glides across the sky.
Wednesday night’s pass takes the ISS essentially overhead. The ISS is moving mostly toward us when it is low in the sky, so it is moving slowly, and it is not yet at its brightest, so it can be hard to spot. The ISS will first appear low toward the northwest, between 6:20 and 6:21 P.M. on Wednesday. Look for Cygnus, the Swan, also known as the Northern Cross, a little west of northwest. The Northern Cross appears to be standing up from the horizon, with its brightest star Deneb, marking the top of the Cross and the tail of the Swan, 25 degrees above the horizon.
The ISS will be moving upward along the west side of the cross between 6:20 and 6:21, passing by Deneb at 6:22 P.M. By 6:23 it will be bright, obvious, and moving by the familiar “W” pattern of stars marking
Cassiopeiae, the Queen. Just before 6:24 the space station will be essentially overhead and appear magnitude -3.9. It will then pass through Perseus while headed toward the southeast. At 6:24 the ISS will
pass south of the pentagon of stars marking Auriga. It will then pass above Orion before moving into the Earth’s shadow just after 6:25 and fading from view. Thursday night’s ISS pass is earlier, so only the brighter stars will be visible, and the space station’s pass will be lower in the sky. At 5:30 P.M. you should be able to spot the star Vega 10 degrees above the northwestern horizon. The ISS will pass above Vega at 5:33. Approaching magnitude -3.6, the ISS will be due north and 46 degrees high just after 5:35:20 (HH:MM:SS). Its path will take it high above the northeastern horizon and then down toward the east southeastern horizon, where it will disappear at 5:40 P.M.