Transient Events That Can Give Us a Good Enough Reason to Get Outside and Do a Little Observing

June 2026

All month:  the solar system provides treats for planet-watchers both at dawn and at dusk this month, with Mercury, Venus, and Jupiter gracing the early evening sky and Mars, Saturn, and Neptune greeting the morning light, while Uranus spends much of the month lost in the Sun’s glare after reaching conjunction on May 22.  In the evening sky, Mercury is the first to set, dropping below Earth’s lid 90 minutes after sunset on June 1 but only 50 minutes after the Sun on June 30.  It fades from mag -0.6 to +2.2 over the course of the month, as its diameter grows from 6 to 11 arcseconds and its lit phase narrows from 70% to 13% (it becomes a fat crescent around June 21).  It’s followed by Venus, which stays up late this month, setting between 10:45 and 11 pm.  Its disk grows from 13 to 16 arcseconds and blazes at mag -4.0 to -4.1 throughout June.  This month also brings our last good views of Jupiter as it careens towards solar conjunction in late July.  Its disk shrinks slightly, from 33 to 32 arcseconds, and it dims imperceptibly from mag -1.9 to -1.8 during the month.  For the morning crowd, Neptune is the first to peek over the horizon, just before 2:30 am as June opens and two hours earlier as it ends.  Its 2¼ arcsecond disk glows faintly at mag 7.9.  It’s closely followed by mag +0.9 Saturn about 20 minutes later.  The rings span 39 arcseconds, exposing the planet’s southern hemisphere to our view.  Their tilt opens from 8° to 9° over the course of the month, while its disk grows slightly, from 32 to 33 arcseconds.  Mars follows about an hour behind Saturn, rising at 3:45 am on June 1 and about an hour earlier on June 30, its 4 arcsecond disk shining at mag +1.3 and still too small for observation of surface features.  Uranus brings up the rear, breaching the horizon at 4:49 am as the month opens and 3:00 am when it ends.  It’s hidden in the solar glare early in the month, then shows us a 3½ arcsecond disk at mag 5.8.  Among the asteroids, 14 Irene will reach opposition on June 15.  It will be brighter than mag 10 all month, as will 18 Melpomene as it cruises towards its own opposition in July.  This month’s charts will show you where to find them.

June 1:  start the month with a view of Mercury, glowing at mag -0.5 and perched 9° above the horizon at 8:58 pm CDT (a half hour after sunset).  Jupiter and Venus are higher and farther left – follow a line between them to lead you to Mercury.  Later, watch a mag 4.6 star pop out from behind the narrow dark edge of the 97% lit Moon at 12:26 am.  Start watching several minutes before then to be sure you don’t miss it.

June 4-13:  the two brightest planets, Venus and Jupiter, sit within 5° of each other each of these evenings, with Castor and Pollux (Alpha [] and Beta [] Geminorum), mag 1.9 and 1.2, off to their right.

June 9:  Mercury will reach dichotomy, when 50% of its disk is lit by the Sun, when the planet is at greatest elongation on June 15 – but due to the Schröter effect, it will appear to be at dichotomy tonight.  You can find it 10° above the horizon at 9:10 pm CDT (45 minutes after sunset), 13° to the lower right of the Venus-Jupiter pair, which are at their closest tonight with only 1.6° separating them.  Look closely at Jupiter to catch the last double shadow transit of this apparition, as the shadow of Callisto crosses the planet from before sunset until after it sets at 10:54 pm, joined by the shadow of Europa until 10:13 pm.

June 13:  a thin crescent Moon, just 5% illuminated, rises almost in tandem with The Pleiades (M45) barely 1° to its lower left around 3 am CDT.  Mag +1.3 Mars looks on from its perch 10° to the right.  Early risers can catch the delicate tableau in binoculars until morning twilight erases the scene around 4:45 am.

June 15-16:  new Moon arrived June 14 at 9:54 pm CDT, so at 8:58 pm on the 15th (a half hour after sunset), it will be a vanishingly-thin crescent just over 1% illuminated, 6° above the horizon and 3° left of the spot where the Sun went down.  Look for it 25° lower right of Venus and 18° lower right of Jupiter, with Mercury 8° from Jupiter along the same line.  On the 16th at 9:14 pm (45 minutes after sunset), it will still be slim at 6% illumination, 12° above the horizon and 12° left of the sunset spot, 10° lower left of Venus and 4½° left of Jupiter, with Mercury 3° almost directly below it.

June 17:  it’s a rare afternoon observing event as the 11% illuminated crescent Moon occults Venus in daylight, high in the SE sky.  The Sun will be at almost the same elevation and 38° to the west, so be sure to position yourself in the shade and keep a solid barrier between your eyes and the Sun.  Start watching by 2:20 pm CDT.  Venus will reach the Moon’s dark edge about 2:23 pm and slowly disappear over the following 2-3 minutes.  It will pop back out at 3:50 pm, but will be much harder to see against the Moon’s bright limb.

June 17-19:  the 12% lit crescent Moon invades The Beehive Cluster (M44) on the 17th, with three planets lined up to the Moon’s lower right:  Venus standing 2½° from the Moon, Jupiter 8° from Venus, and Mercury 6° beyond Jupiter and 6° above the horizon at 9:29 pm CDT (an hour after sunset).  You’ll need binoculars to spot any of the cluster’s stars.  Get there earlier if you want to see Callisto, the most distant Galilean moon, slip behind the planet and disappear at 9:10 pm.  Over the next two nights, Venus inches progressively closer to the cluster, approaching to 1.3° on the 18th and 45 arcminutes on the 19th before slowly withdrawing.

June 20:  the almost-first-quarter Moon is hungry tonight, gobbling up mag 5.2 star 75 Leonis at 8:49 pm CDT and its mag 5.9 neighbor 59 Leonis at 10:03 pm, just after 75 Leo emerges from the opposite side.  Both stars disappear into the middle of the Moon’s dark limb.

June 21:  the solstice arrives at 3:25 am CDT, promising a few months of short but warm observing nights.

June 24: Mercury will be a challenge tonight, but worth the effort to see it as a 21% illuminated crescent.  At 9:16 pm CDT (45 minutes after sunset), it will be a dim mag +1.3 target 5° above the horizon, 10° left of the spot where the Sun went down, and  3½° below right of Jupiter.  Venus looks on from farther above left.

June 27:  the almost-full Moon unsuccessfully chases ruddy Antares (Alpha [] Scorpii) across the southern sky tonight, trailing its starry quarry by almost 6° and not gaining a step all night.

June 29:  early risers get a pretty binocular view as mag +1.3 Mars rises 5° below right of The Pleiades (M45) shortly before 3 am CDT.  The pair will reach 15° elevation by 4:17 am (an hour before sunrise).

June 30:  mag 5.8 Uranus is a relatively easy catch with binoculars, 10° above the ENE horizon by 4:03 am CDT (75 minutes before sunrise), 3° below left of mag +1.3 Mars and 5° directly below The Pleiades (M45).

Rick Gering / June 2026