Skywatch Line for Wednesday and Thursday, March 26 and 27, 2025, written by Alan French
This is Dudley Observatory’s Skywatch Line for Wednesday and Thursday, March 26 and 27, 2025, written by Alan French.
The Sun rises at 6:47 A.M. on Wednesday and sets at 7:15 P.M. On Thursday it rises at 6:46 A.M. and sets at 7:16 P.M. Thursday gained 20 minutes 57 seconds of daylight compared to last Thursday. By the end of March we will have grained just over 1 hour, 40 minutes of daylight.
The Moon reached last quarter Saturday and is headed toward new. A slender, waning crescent Moon will be low in the sky before sunrise. On Wednesday at 6 A.M. look for the 12% sunlit Moon 4 degrees above the horizon toward the east southeast. By 6:15 it will be just over 6 degrees high. Thursday the Moon, less than 6% illuminated, does not rise until 5:57 A.M. By 6:15 it will be just 2 ½ degrees above the horizon toward the east. The Moon will reach new Saturday morning.
There is fine pass of the International Space Station (ISS) over our area on Thursday evening. It will pass almost overhead under dark skies and move into the Earth’s shadow and fade from view while well above the horizon.
Look for the space station coming up from the west northwestern horizon at 8:42 P.M. It is fainter when low in the sky and appears to move slowly since it is moving mostly toward us. It brightens and moves faster among the stars as it rises higher into the sky. By 8:43:45 (HH:MM:SS) the ISS will be 15 degrees high and moving toward Perseus. After moving through Perseus, it will pass just northeast of the rough pentagon of stars outlining Auriga, the Charioteer.
The ISS will pass close to Capella, the brightest star in Auriga, just before 8:45. As it approaches its highest point, it will reach its maximum brightness, magnitude -3.8, brighter than any object then in the night sky. It will pass northeast of Gemini, the Twins, and Mars, and then head down toward the southeastern horizon.
As it moves toward the horizon, it will pass close by Regulus, the brightest star in Leo, the Lion, and then move into the Earth’s shadow and fade from view, vanishing while well above the horizon. How far can you follow it?
The ISS now orbits the Earth in an orbit with a maximum height of 419km (260 miles) and a minimum height of 414km (257 miles). Drag from the Earth’s atmosphere slows it down, causing it to lose altitude, so it must be given an occasional boost to move it into a higher orbit.