Skywatch Line for Wednesday and Thursday, June 21 and 22, 2023

This is Dudley Observatory’s Skywatch Line for Wednesday and Thursday, June 21 and 22, written by Alan French.

At 10:58 A.M. on Wednesday we reach the Summer Solstice, when the Sun is farthest north and highest in our sky. After the Solstice, our days will begin growing shorter again, slowly at first, as the Sun moves south and lower in our sky.

The Sun rises at 5:17 A.M. on Wednesday and sets at 8:37 P.M. On Thursday it rises at 5:17 and sets at 8:37. This Thursday has just over 1 minute more daylight than last Thursday.

It’s fun to find Venus in the daytime sky. The planet is often bright enough to spot by eye alone, the trick is finding it against the bright blue sky. A few high clouds can sometimes aid the search, giving the eye something to focus on.

Unfortunately, the high altitude smoke from the Canadian wildfires may preclude finding Venus by eye alone, but on Wednesday the planet’s proximity to the Moon may aid the search, and searching with binoculars should overcome the difficulty caused by the wildfire smoke. Indeed, it’s usually easier to first find Venus with binoculars, and then try spotting it by eye.

Whether searching by eye or with binoculars, a reclining lawn chair makes for an agreeable search. Set it up in the shade to the east of a building where there’s a good view to the south. Setting up in the shade guarantees you cannot accidentally sweep up and look at the the Sun, and being in the shade makes for more comfortable searching.

The best time to start the search is when the Moon, a thin crescent, is due south and highest, which will be at 3:55 P.M. on Wednesday afternoon. The Moon will be just over 69 degrees above the horizon, and will probably seem closer to overhead than you expect. Be sure to first focus your binoculars carefully on a distant object or, better yet, a high-flying plane. In mid-afternoon Venus will be 4 ½ degrees below the Moon and a little to the left. Most binoculars will fit the Moon and Venus in view at the same time.

The Moon was new early last Sunday and is now moving toward first quarter. As darkness falls on Wednesday, a slender crescent Moon and Venus will make a lovely pair in the western sky. At 9:00 P.M. the Moon, just over 13% illuminated, will be 25 degrees above the western horizon and brilliant Venus will be just over 3 degrees to the Moon’s lower left. At 9:30 P.M. the Moon will be 20 degrees high and Venus will be slightly closer.

By Thursday night the Moon’s eastward motion among the stars will have moved it away from Venus. At 9:00 P.M. a 20% sunlit crescent Moon will be 30 degrees above the western horizon with Venus to its lower right. The pair will be 10 degrees apart.

On either night the pair would be good subjects for a photograph, especially with a nice foreground.