Mercury is nicely situated for evening viewing for northern hemisphere sky watchers as June starts. It’s quickly moving from next to Auriga into Gemini. A thin, crescent moon passes by on the 4th. The moon is passing Mars in the middle of Gemini the next evening. Mars seems to be moving away from Mercury, going east, but the messenger planet is fast catching up. Watch the two planets for several evenings before and after the 18th when they’re closest. For the rest of the month, Mercury slows down and begins to recede back into the sunset’s glow. At the end of June, both planets are between Gemini and Cancer.
Mercury is dim and often a challenge to identify. Its quick movement among the bright stars of Gemini and close call with Mars will be a big aid this month. Even with Mercury at its greatest elongation from the sun, you won’t get a lot of dark sky time to observe it in. So find a horizon as free of trees, hills, buildings, and other obstructions as you can. Observe every evening that you can and learn the stars around the planet. You don’t have to know their names, but knowing where they are helps you see right away which object is Mercury. It’s the object that’s moving among the other ones that are keeping the same relative positions.
Jupiter is a mid-evening riser somewhat close to Antares. Saturn rises in the middle of the night. Both planets are retrograde on opposite sides of Sagittarius. The moon is close to Jupiter on the 15th and 16th. It’s close to Saturn on the 18th and 19th.
A thin, waning, crescent moon passes by Venus on the morning of the 1st. Venus stays close to the horizon just before sunrise all month.
Earth is at northern solstice on June 21.
The moon’s conjunctions this month:
3.1° from Venus on the 1st
3.6° from Mercury on the 4th
1.6° from Mars on the 5th
6.1° from Pollux on the 6th
3.0° from Regulus on the 8th
7.2° from Spica on the 12th
0.9° from Ceres on the 15th
7.7° from Antares on the 16th
2.0° from Jupiter on the 16th
0.4° from Saturn on the 19th
3.6° from Neptune on the 24th
4.5° from Uranus on the 28th
2.2° from Aldebaran on the 30th
Venus 4.7° from Aldebaran on the 17th
Mercury 0.2° from Mars on the 18th
Mercury 5.5° from Pollux on the 19th
Mars 5.5° from Pollux on the 21st
A swath of Earth from the southeast Pacific Ocean, across the southern tip of South America, and over the far southern Atlantic Ocean will be in the path of an occultation of Saturn on the 19th. The moon will pass in front of the ringed planet at different times for different locations. The central conjunction time is 03:46 UT.
June is the month with the shortest nights in the northern hemisphere. And the mosquitoes are very active. So enjoy what you can and use insect repellant.