For June 2025, the first quarter moon is on June 2. The full moon, the Honeymoon, is June 11th. Last quarter moon is June 18th. Summer begins at 10:42 p.m. with the solstice, the longest day, with 14 hours of sunlight locally. The waning crescent moon is passing above Saturn in the dawn on June 19, and just north of Venus on June 22nd. The moon is new on June 25th. The waxing crescent moon passes Mercury in the west on June 26th.
This June Mercury passes Jupiter low in the NW at dusk on June 5th. Jupiter becomes lost in the Sun’s glare for the rest of the month, but Mercury is visible low in the west for the rest of June, with the nicest grouping with the crescent moon and the Gemini, Castor and Pollux, all in a row in twilight; great photo op for smartphones! Mercury is at greatest elongation, 26 degrees east of the Sun, on July 4, but quickly gets lost in the Sun’s glare by mid month.
Venus dominates the dawn sky. She reaches greatest western elongation, 46 degrees ahead of the rising sun, on June 1st, and will appear half lit in telescopes. After that, it pulls away from the earth, shrinking in size but appearing gibbous in phase for the next several months.
Mars is still visible in the western evening sky, and makes a nice grouping with Regulus in Leo on June 16th, passing just over a lunar diameter (.8 degrees) north. While comparable in brightness then, Mars of course will be much redder than blue Regulus.
While Jupiter passes directly behind the Sun on June 24th, Saturn is well placed for dawn observers, who can see the rings, edge on for the last several weeks, tilting more open each morning. The rings continue opening until their solstice in 2032, when they will tilt 27 degrees toward the Sun and more than double the planet’s present brightness. It is still the brightest object in the southern fall sky now, in Pisces.
The Big Dipper is almost overhead as twilight falls, and its pointers take you north to the Pole Star. If you drop south from the bowl of the Big Dipper, Leo the Lion is in the SW. Note the Egyptian Sphinx is based on the shape of this Lion in the sky. Taking the arc in the Dipper’s handle, we "arc" SE to bright orange Arcturus, the brightest star of Spring. Cooler than our yellow Sun, and much poorer in heavy elements, some believe its strange motion reveals it to be an invading star from another smaller galaxy, now colliding with the Milky Way in Sagittarius in the summer sky. Moving almost perpendicular to the plane of our Milky Way, Arcturus was the first star in the sky where its proper motion across the historic sky was noted, by Edmund Halley.
Spike south to Spica, the hot blue star in Virgo, then curve to Corvus the Crow, a four sided grouping. North of Corvus, in the arms of Virgo, is where our large scopes will show members of the Virgo Supercluster, a swarm of over a thousand galaxies about 50 million light years distant.
South of Corvus lies the famed Southern Cross, but only its top three stars are BARELY visible on the Gulf horizon for us. But much of the rest of Centaurus is visible, and two notable deep sky objects beckon binocular viewers. The easiest is Omega Centauri, the grandest globular cluster in the sky. Visible as a circular blur with the naked eye, it can be resolved into some stars with even large binoculars. In my See Star S 50, it is a great sight with clear skies, despite being only eight degrees high in the south!
Just a few degrees above Omega, Centaurus A is the most powerful radio galaxy in our neighborhood. Two great galaxies, each as massive as our own Milky Way, are colliding and merging before our eyes. In the middle is a giant elliptical, a ball of billions of older reddish stars but a thousand times more populated that Omega. Its black hole is pulling core of a spiral galaxy, not that different from our own, toward the core, while the spiral arms of the victim still lie silhouetted in front of the collision. All this collision of gas and dust is stirring up star formation at a furious pace, hence it is called a "starburst" galaxy, and its output of all forms of energy is indeed off the scale.
To the east, Hercules is well up, with the nice globular cluster M-13 marked on your sky map and visible in binocs. The brightest star of the northern hemisphere, Vega (from Carl Sagan’s novel and movie, "Contact"), rises in the NE as twilight deepens. Twice as hot as our Sun, it appears blue-white, like most bright stars. They are bright because they are hot, even though on the main sequence, fusing hydrogen like our Sun, they are only a little larger than our home star.
Northeast of Lyra is Cygnus, the Swan, flying down the Milky Way. Its bright star Deneb, at the top of the "northern cross" is one of the luminaries of the Galaxy, about 50,000 times more luminous than our Sun and around 3,000 light years distant. Our solar system is orbiting the core of our own Galaxy every 250 million years, and currently moving in the direction of a point, our Apex, midway between Deneb and Vega.
Under dark skies, note the "Great Rift", a dark nebula in front of our solar system as we revolve around the core of the Milky Way in the Galactic Year of 250 million of our own years. The effect of our Sun and planets passing through such dusty regions as this is debated, and may effect our long term climate and even our Ice Ages. Warning, this cooling can not be in time to fix our present global warming issues!
To the east, Altair is the third bright star of the summer triangle. It lies in Aquila the Eagle, and is much closer than Deneb; it lies within about 13 light years of our Sun. Use your binocs to pick up many clusters in this rich region of our own Cygnus spiral arm rising now in the east. The nearest spiral arms of our Milky Way are now on the eastern horizon, and may be mistaken for a cloud rising if you are not used to the transparency of rural skies! They arc overhead in the morning hours for restless campers. To the south, Antares is well up at sunset in Scorpius.
It appears reddish (its Greek name means rival of Ares or Mars to the Latins) because it is half as hot as our yellow Sun; it is bright because it is a bloated red supergiant, big enough to swallow up our solar system all the way out to Saturn’s orbit! Scorpius is the brightest constellation in the sky, with 13 stars brighter than the pole star Polaris! Note the fine naked eye clusters M-6 and M-7, just to the left of the Scorpion’s tail. Just a little east of the Scorpion’s tail is the teapot shape of Sagittarius, which lies toward the center of the Milky Way. From a dark sky site, you can pick out the fine stellar nursery, M-8, the Lagoon Nebula, like a cloud of steam coming out of the teapot’s spout.
