As June begins, bright Jupiter is very low in the west-northwest twilight, and Mars is far to its upper left; they’re the only evening planets. Begin following Jupiter while it’s easy to see at the start of the month, and let the departing giant be your guide to emerging Mercury for a few evenings around June 7. A few days later, Jupiter disappears, and Mercury replaces it.
Bright stars at dusk include the Arch of Spring: Procyon is low in the west, with Pollux-Castor 4.5° apart at the apex, and Capella low in the northwest. Jupiter is below the arch, while Mars and Regulus appear to the arch’s upper left. Other bright stars at dusk are golden Arcturus and blue Spica crossing the southern sky, and blue-white Vega, with Deneb in the northeast quadrant.
Later in evening, or in twilight later in June, watch for Altair rising to complete the Summer Triangle with Vega-Deneb. Red supergiant Antares, having just passed opposition on May 30, begins June low in the southeast at dusk.
The morning twilight scene is dominated by Venus, low in the east. Reaching a maximum angular separation from the sun (greatest elongation) of 46° on June 1, Venus, as seen through a telescope, reveals a “half-moon” phase, 24” (arcseconds) across. By month’s end, Venus fills out to 63 percent full, but shrinks to 18” across, as the faster-moving inner planet recedes to a distance 21 million miles farther from us.
Far to Venus’ upper right, Saturn will lie directly ahead of Spaceship Earth on June 22. This month, we’ll move 44 million miles closer to this slow-moving giant planet. Saturn’s rings are inclined only 3.1° to 3.6° from edge-on during June, while the sun illuminates them only dimly from an angle only 0.4° to 0.8° off their plane. Under these conditions, the rings appear as a dim, narrow line crossing the planet. Bright stars visible at dawn include Arcturus and Antares, about to set in west-northwest and southwest; the Summer Triangle of Vega, Deneb and Altair overhead; Fomalhaut, Mouth of the Southern Fish, in the southeast quadrant; Capella, rising in the far north-northeast to northeast; and finally, Aldebaran, eye of Taurus, rising in the east-northeast twilight before month’s end.
Moon and planetary events calendar for June 2025: Many of the following events are illustrated on the Sky Calendar. Subscriptions are available at www.abramsplanetarium.org/skycalendar; for $12 per year, subscribers receive quarterly mailings, each containing three monthly issues. A map depicting the month’s evening sky appears on the reverse of each sheet.
Sunday, June 1 at dusk: The star Regulus, marking the heart of Leo, the Lion, appears about 1° to the lower left of the fat, 40 percent crescent moon, one day before first quarter phase. Tonight, Mars appears 8°-9° to the lower right of the moon and Regulus.
June 2 at dawn: Saturn, magnitude +1.1, appears 26° to the upper right of Venus, the brilliant morning “star” of magnitude -4.4 in the east. Just before twilight begins, use a telescope or large binoculars to detect faint Neptune, 1.5° to the upper left of Saturn.
June 5, early dusk: You’ll need binoculars, very clear skies and an unobstructed view of the horizon to see Mercury (magnitude -1.5) in bright twilight 30 minutes after sunset, just more than 5° to the lower right of Jupiter (magnitude -1.9). Watch daily for changes, as Jupiter appears lower each night, with Mercury higher. As the sky darkens tonight, look for Spica, the spike of grain in the hand of Virgo, 5° to the lower left of the 77% waxing gibbous moon. Tomorrow, Mercury will appear 3.6° to the lower right of Jupiter, and Spica will appear 7° to the upper right of an 85% moon.
June 7, 30 minutes after sunset: Mercury (magnitude -1.2) has now climbed slightly higher than Jupiter, 2.3° to its right.
June 8, 30 minutes after sunset: The largest and smallest planets of our solar system appear closest tonight, with Mercury (magnitude -1.1) 2.1° to the upper right of brighter Jupiter (magnitude -1.9). Antares, heart of the Scorpion, appears 15° to the lower left of the 95% moon as the sky darkens.
June 9, 30 minutes after sunset: Can you still see Jupiter? It’s almost gone, 3.1° below Mercury. Jupiter will be in solar conjunction on far side of the sun on June 24, while Mercury climbs higher in the west-northwest twilight glow until June 27 as seen from the Coachella Valley. When it climbs higher, you’ll be able to spot it as much as an hour or more after sunset.
As the sky darkens on June 9, look for Antares just 3° to the lower left of the 99% moon in the southeast. By about two hours before sunrise on June 10, the moon will creep about 1° below Antares in the southwest.
In the evening sky June 9-24, Mars and Regulus will appear closer together than Pollux and Castor, the “Twin” stars of Gemini. The Mars-Regulus pairing will be most striking when closest, within 0.8° apart on June 16 and 17.
June 10, at dusk: Find Antares 9° to the upper right of the moon, which will be full overnight, at 12:44 a.m. early Wednesday morning, June 11.
The nights of June 10-11 and June 11-12 present the southernmost full moon of this year; and the southernmost moonset. These passages will be strikingly farther south than the path of December’s winter solstice sun.
After the full moon, moonrise occurs later each night, and the waning moon is conveniently observed daily before dawn.
By mid-June, Jupiter is lost in the glare of evening twilight, and Mercury and Mars are the only planets still visible at dusk. Both offer striking displays. Mercury, below the “Twin” stars Pollux and Castor, forms a nearly isosceles triangle with them for two evenings: On June 15, Mercury is about 10 3/4° from each, and on the next evening, about 9 1/3° from each. Mars appears very close to Regulus on June 16 and 17, as described above. Mercury passes 5° south (to the lower left) of Pollux on June 21, and lies in a straight line 11 1/4° long with the Twin stars while passing 6 3/4° left of Pollux on June 24. Reminder: June 24 is the last evening that Mars-Regulus appear closer together than Pollux-Castor (4.3° vs. 4.5°).
Let’s shift back nearly a week to the morning of June 18 to check on the waning moon in the predawn sky. On the 18th, 1 1/4 hours before sunrise, the 54% moon is high in the southeast, 8° to the upper right of Saturn. The next morning, find the 43% fat crescent within 7° to the lower left of Saturn. On June 20, the 31% moon has gone nearly halfway across the 43° gap from Saturn toward Venus. Summer begins later that day, at 7:42 p.m.
On June 22, the 12% crescent moon appears within 8° to the upper left of Venus. Using binoculars, can you spot the Pleiades cluster, 9° to the moon’s lower left? Any day now, watch for the rising of Aldebaran, eye or Taurus, nearly 14° below this “Seven Sisters” star cluster. On June 23, the 6% crescent moon is 19° to the lower left of Venus, and 6° to the lower left of the Pleiades. With binoculars, locate 5.8-magnitude Uranus 4°-5° to the lower right of Pleiades, and 8° to the upper right of the moon, and watch for Aldebaran rising 10° to the lower right of the lunar crescent.
One last chance to see the waning moon occurs on June 24. The best time to see it might be a little less than an hour before sunrise, when the hairline one-percent crescent will appear just above the northeast to east-northeast horizon, 33° to the lower left of Venus. After the new moon, the first chance to see the young crescent will occur in early dusk on June 25. You’ll need binoculars, a near-perfect sky, and an unobstructed view of the horizon 30° to 33° north of due west.
In June’s five remaining evenings, watch the waxing crescent moon skate past two planets and three bright zodiacal stars. On June 26, about an hour after sunset, find Mercury 3° to the left of the 4% crescent moon, and Pollux and Castor within 6° and 10° to the moon’s right. On June 27, the 10% moon appears 10° to Mercury’s upper left. Regulus and Mars, 6° apart, await 18° and 24° to the moon’s upper left.
On June 28, Regulus lies 5° to the upper left of the 17% crescent, while Mars lies another 6.6° to the upper left of Regulus. On June 29, Mars lies only about a degree to the right of the 25% crescent, with Regulus now 8° to the moon’s lower right. Mercury, faded to magnitude +0.2, is low in the west-northwest, 26° to the lower right of Regulus. On June 30, the moon, 34% full in the west-southwest, aligns with Mars, Regulus and Mercury, 13°, 21° and 46° to its west (lower right), respectively.
The Astronomical Society of the Desert will host a star party on Saturday, June 21, at Sawmill Trailhead, a site in the Santa Rosa Mountains at elevation 4,000 feet; and on Saturday, June 28, at the Santa Rosa and San Jacinto Mountains National Monument Visitor Center. For more information, including maps and directions to the two observing sites, visit astrorx.org.
Robert Victor originated the Abrams Planetarium monthly Sky Calendar in October 1968 and still helps to produce an occasional issue. He enjoys being outdoors sharing the beauty of the night sky and other wonders of nature.