Skywatch Line for Wednesday and Thursday, June 18 and 19, 2025, written by Alan French
This is Dudley Observatory’s Skywatch Line for Wednesday and Thursday, June 18 and 19, 2025, written by Alan French.
The Sun rises at 5:16 A.M. on Wednesday and sets at 8:37 P.M. On Thursday it rises at 5:17 A.M. and sets at 8:37 P.M. Thursday gained 2 minutes, 19 seconds of daylight over last Thursday. This Thursday has 15 hours, 20 minutes, 17 seconds of daylight. Friday will have 4 seconds more daylight, then we will be past the summer solstice and start losing daylight, slowly at first, as the Sun begins moving south and lower in our skies.
The Moon was full late last Thursday afternoon and is now headed for last quarter and rises after midnight. An hour before sunrise on Wednesday morning, the Moon will be in the southeast with Saturn, shining at magnitude +1.1, to its east, 7 degrees away. The Moon will be a 55% sunlit and 33 degrees high. Moonset will be at 12:48 P.M. in the west.
The Moon reaches last quarter mid-afternoon on Wednesday and begins moving toward new. An hour before sunrise on Thursday the Moon, its visible face now 43% in sunlight, will be 32 degrees above the east southeastern horizon. It will set at 2:02 in the afternoon.
If you are up in either morning looking at the Moon, brilliant Venus, now at magnitude -4.2, will be low toward the east.
Mars and Regulus, the brightest star in Leo, were less than a degree apart on Tuesday night, but the skies were predicted to be cloudy. They will be moving farther apart, but perhaps the skies will be more cooperative on Wednesday or Thursday. They will still be close together.
Leo, the Lion, is low in the west when the brighter glow of twilight is gone at 10 P.M. The most obvious part of Leo’s stellar outline is a backwards question mark of bright stars outlining his head, tipped to the right. The bottom star, the brightest in Leo, is Regulus. It is now accompanied by Mars, with Mars above Regulus. Regulus shines at magnitude +1.34 and Mars is magnitude 1.4, so they appear the same brightness. Mars’ reddish color makes it stand out,
At 10 P.M. Tuesday the pair was 46 arcminutes apart, three-quarters of a degree. On Wednesday they will be just over 1 degree apart, and by Thursday the separation will be 1 ½ degrees.
Regulus is almost exactly on the ecliptic, so it is occasionally close to a planet and often the Moon and regularly occulted by the Moon. On rare occasions it is occulted by Mercury or Venus. It was last occulted by Venus on July 7, 1959, and will next be hidden by Venus on October 1, 2044.
If you look to the upper left of Leo’s head, you will see a triangular pattern of bright stars narrowing to its upper left. These stars mark Leo’s hindquarters. The uppermost star is Denebola, the second brightest star in Leo. It marks the lion’s tail.