Skywatch Line for Wednesday and Thursday, April 24 and 25, 2024, written by Alan French

This is Dudley Observatory’s Skywatch Line for Wednesday and Thursday, April 24 and 25, 2024, written by Alan French.

The Sun rises at 5:59 A.M. on Wednesday and sets at 7:49 P.M. On Thursday it rises at 5:57 and sets at 7:50. This Thursday has 18 ¾ minutes more daylight than last Thursday. By the end of April, we will have gained just over 1 hour, 22 minutes, and 30 seconds of sunlight of sunlight. The last day of April will have 14 hours, 5 minutes, and 11 seconds of daylight.

The Moon was full on Tuesday so it is now heading toward last quarter. A waning gibbous Moon now rises a bit later each evening. On Wednesday the Moon rises in the east southeast at 8:55 P.M., appearing almost 99% sunlit. The Moon will be due south and 26 degrees above the horizon at 1:46 A.M. Thursday morning. Thursday the Moon rises, a bit more toward the east, at 10:03 P.M. It will be 95% illuminated. The terminator, the line between sunlight and darkness on the Moon, is now the sunset line. The Moon will reach last quarter on Wednesday, May 1.

On Wednesday night, there is a nice pass of the Chinese space station, Tiangong, over our area. The times and path are given for Schenectady, but should be close enough for anyone in the surrounding region. When high in the sky, the space station is bright and easy to spot.

Tiangong’s path will take it from west to east and it will travel high across the southern sky. Civil dusk, when the center of the Sun is six degrees below the horizon, is at 8:19 P.M. At Civil Dusk the brightest stars and planets are visible. The station will first be visible between 8:37 and 8:38 P.M., when the Sun will be almost 9 degrees below the horizon, so more brighter stars should be visible.

Look for Tiangong coming up from the western horizon between 8:37 and 8:38. When it is low it is moving mostly toward us, and its brightness is reduced by the thick layer of atmosphere, so it can be hard to spot. As it moves higher its apparent motion increases and it brightens, becomes easier to see. By 8:38 it will be 14 degrees high.

At 8:39 Tiangong will pass above Betelgeuse, 27 degrees above the west southwestern horizon and possibly visible against the twilight glow. Just before 8:40:30 P.M. the station will be due south, 60 degrees above the horizon, and about to pass above Regulus, the brightest star toward the south. It will also be at its brightest, shining at magnitude -2.1. At 8:42 it will be low in the east southeast and about to move into the Earth’s shadow and fade from view.

There are currently three astronauts aboard Tiangong. There arrived on October 26, 2023. There are 7 people aboard the International Space Station.