Skywatch Line for Wednesday and Thursday, May 21 and 22, 2025, written by Alan French
This is Dudley Observatory’s Skywatch Line for Wednesday and Thursday, May 21 and 22, 2025, written by Alan French.
The Sun rises at 5:27 A.M. on Wednesday and sets at 8:19 P.M. On Thursday it rises at 5:26 A.M. and sets at 8:19 P.M. Thursday, with 14 hours, 52 ¾ minutes of daylight, gained 13½ minutes of daylight over last Thursday.
The Moon reached last quarter Tuesday and is moving toward new. It rises well after midnight and is best seen in the pre-dawn hours. On Wednesday morning at 5 A.M. a 40% sunlit Moon will be 25 degrees above the southeastern horizon. You will also see brilliant Venus, shining at magnitude -4.4, 15 degrees above the eastern horizon and 33 degrees away from the Moon. Roughly midway between the Moon and Venus is Saturn, less obvious at magnitude +1.1. It will be more obvious earlier, around 4:30
A.M., when morning twilight is less intrusive.
By Thursday morning the Moon’s eastward motion among the stars will have brought it close to Saturn. The closeness of the bright Moon might make Saturn easier to spot at 4:30. Binoculars may still aid the view of Saturn, only 4 degrees away from the Moon.
The Moon reaches new just before midnight on Monday, May 26.
The ISS (International Space Station is visible both nights, with its highest and brightest pass on Wednesday night.
We see the ISS because it is still up in sunlight while we are down in the Earth’s shadow and darkness. It is the brightest object now it orbit because it is large and reflects a lot of sunlight. Its maximum magnitude when high in the sky is now
-3.8, brighter than any planet except Venus.
On Wednesday night the ISS will reach a maximum magnitude of -3.6 and it will move into the Earth’s shadow and fade from view while still high in the sky.
Look for the ISS moving up from the west northwestern horizon at 10:31 P.M. Its path will take it north of bright Capella, low in the northwest, and south of Castor and Pollux, . Soon after 10:34 the space station will pass about half way between Polaris, the North Star, and the bowl of the Big Dipper. It will then pass above the bowl of the
Little Dipper and head toward the Keystone of Hercules in the east. As it approaches Hercules it will move into the Earth’s shadow and fade from view just after 10:35.
Thursday night’s pass of the ISS will follow roughly the same path but will be earlier in the evening and lower in the sky. Look for the ISS low in the northwest at 9:43 P.M. At 9:44 the station will pass close to Capella, the brightest star low in the northwest lying 17 degrees above the horizon. The ISS will the travel across the northern sky, passing just below Polaris at 9:46 and then traveling through the stars of Draco, the Dragon. After 9:47 it will pass near Vega and then head down toward the eastern horizon, moving into the Earth’s shadow and disappearing before reaching the horizon.