This Week's Sky at a Glance, June 12 – 21

FRIDAY, JUNE 12

■ Venus and Jupiter continue their twilight show, but that thing they had going together a few days ago just didn't seem to work out. They're breaking up and going their separate ways. Even Mercury, watching from below, has lost interest in them and is starting to drop back down, fading all the while.

But final act of the drama continues. This evening Venus and Jupiter are still just 3½° apart, about two finger-widths at arm's length, still making an eye-grabbing celestial duo by anyone's standards as twilight fades toward night:

SATURDAY, JUNE 13

■ And now Venus and Jupiter have widened to 4½° apart. That's the same separation as the Gemini twins Pollux and Castor, which emerge into view to their right as twilight deepens.

■ Most of the springtime is Milky-Way-less for us living at mid-northern latitudes; the Milky Way lies right down out of sight all around the horizon in the evening. But now spring is ending.

Look east after the night is fully dark. Looming up across the eastern sky is the rich stretch of the summer Milky Way running through Cepheus, Cygnus, Aquila, and Scutum, left to right. It lifts higher every hour and every week. A hint for the light-polluted: The Milky Way runs horizontally under Vega, along the bottom edge of the Summer Triangle.

SUNDAY, JUNE 14

■ Bright Arcturus, shining very high toward the south these evenings, and Spica, about three fists at arm's length below it and a bit right, form an almost perfect equilateral triangle with dimmer Denebola, Leo's 2nd-magnitude tail tip, off to their right. All three sides of the triangle are close to 35° long (35.3°, 35.1°, and 32.8°). Sky & Telescope columnist George Lovi named this the Spring Triangle (in the March 1974 issue), to go with those of summer and winter. For such a near-perfect equilateral, I say the name ought to be perpetuated.

■ New Moon (exact at 10:54 p.m. EDT).

MONDAY, JUNE 15

■ After nightfall, look for the Big Dipper hanging straight down by its handle high in the northwest. Its bottom two stars, the Pointers, point right or lower right toward modest Polaris, the end of the Little Dipper's handle.

This is the time of year when, at the end of twilight, the Little Dipper floats straight upward from Polaris — perhaps like a helium balloon on a curving string escaped into the night from a prom party. Through light pollution, however, all you may see of the Little Dipper are Polaris at its bottom and Kochab, the lip of the Little Dipper's bowl, at the top. Both are 2nd magnitude. The rest of its stars are fairly dim at 3rd to 5th magnitude.

TUESDAY, JUNE 16

■ Venus, Jupiter, and Mercury now form an equally spaced line in twilight, 7° from planet to planet. The thin crescent Moon joins them, hanging between Jupiter and Mercury as shown below.

WEDNESDAY, JUNE 17

■ Today's daylight occultation of Venus by the Moon's dark limb, if you have a clear blue sky at the time, will be visible with a telescope or possibly even binoculars. See the June Sky & Telescope, page 48, for a timetable and details. Nearly everyone in North America gets a chance, sky permitting.

■ During dusk the crescent Moon decorates the top of the Venus-Jupiter-Mercury line. It shines just 2° or 3° upper left of Venus (for North America).

THURSDAY, JUNE 18

■ And now we have a diagonal lineup of five objects in the western dusk 1st-magnitude or brighter. From upper left, spot Regulus, the Moon, Venus, Jupiter, and Mercury. The whole line is 44° long along the ecliptic.

FRIDAY, JUNE 19

The Moon is a thick crescent in the west, left of Regulus. A telescope this evening shows the Moon's terminator crossing, from north to south, Mare Frigoris, Lacus Somniorum, Mare Tranquillitatis, and Mare Nectaris, as shown below. On the south edge of Nectaris is the standout flooded crater Fracastorius, always a landmark when the Moon is near this phase. Just south of Fracastorius, shadows fill the similar-sized craters Piccolomini and more ragged Stiborius.

SATURDAY, JUNE 20

■ On this final evening of spring, look very low in the north-northwest in late twilight for wintry Capella twinkling far out of season. The farther north you are the longer Capella hangs in. For the South it's well and truly gone, but if you're as far north as Montreal or either of the Portlands (Oregon or Maine), Capella is actually circumpolar.

SUNDAY, JUNE 21

■ This is the longest day of the year for the Northern Hemisphere, and the official start of summer. The summer solstice comes at 4:25 a.m. EDT, when the Sun ends its northward journey for the season and begins its six-month return south. The Sun today crosses the highest it can ever be in your sky (if you're in the North Temperate Zone), so this is when your shadow becomes the shortest it can ever be at your location. It happens at local apparent noon ("solar time"), which at your location is probably rather far removed from noon by the clock.

This is also the day when the Sun rises and sets farthest north on your horizon. Though the difference is extremely slight for several days before and after.

■ First-quarter Moon (exact at 5:55 p.m. EDT). After dusk, look for 1st-magnitude Spica about two fists to the Moon's left or upper left, and 2nd-magnitude Denebola, tail star of Leo, the same distance to the Moon's upper right. Corvus is on its way to setting to the Moon's lower left.

The Moon's straight terminator has now unveiled all of Tranquillitatis and Serenitatis.

This Week's Planet Roundup

Mercury is fading; look for it to the lower right of Venus and Jupiter in the western twilight. Mercury is still magnitude +0.4 on Friday the 12th but fades to + 0.9 by Friday the 19th. You might find it most easily visible an hour after sunset.

Venus and Jupiter, the two brightest planets, continue to shine together in the west during and just after twilight. Venus is the brighter one at magnitude –4.0. Jupiter is an eighth that bright at magnitude –1.8. On Friday the 12th they're still just 3.5° apart. By the 19th they widen to 10°.

Both are in Gemini, as is Mercury. Spot Pollux and Castor to the right of Jupiter. Pollux is slightly the brighter of the two "twin" Gemini heads.

On Tuesday the 16th, Venus, Jupiter, and Mercury form an equally spaced line, 7° from planet to planet, with the crescent Moon joining in.

Mars, magnitude +1.3, remains very low in the east as dawn brightens. Hunt for it about three fists to the lower left of much easier Saturn.

Saturn, magnitude +0.8, rises about an hour before the first glimmer of dawn. Catch it in the east-southeast as dawn begins to brighten. Nothing else there is as bright.

Just don't confuse steady Saturn with flickering Fomalhaut, its near-twin in brightness, twinkling way off in the south-southeast three or four fists to Saturn's right.

Uranus, magnitude 5.8, is hidden in the bright sunrise glow.

Neptune, magnitude 7.9, hides about 9° from low Saturn before dawn. Not until well into the summer will Saturn and Neptune enter the evening sky. Mars won't do so until nearly the end of the year.

All descriptions that relate to your horizon — including the words up, down, right, and left — are written for the world's mid-northern latitudes. Descriptions and graphics that also depend on longitude (mainly Moon positions) are for North America. Eastern Daylight Time (EDT) is Universal Time minus 4 hours. UT is also known as UTC, GMT, or Z time.

Want to become a better astronomer? Learn your way around the constellations. They're the key to locating everything fainter and deeper to hunt with binoculars or a telescope.

This is an outdoor nature hobby. For a more detailed constellation guide covering the whole evening sky, use the big monthly map in the center of each issue of Sky & Telescope, the essential magazine of astronomy.

For the attitude every amateur astronomer needs, read Jennifer Willis's Modest Expectations Give Rise to Delight.

Once you get a telescope, to put it to good use you'll want a much more detailed, large-scale sky atlas (set of charts). The basic standard is the Pocket Sky Atlas, in either the original or Jumbo Edition. Both show all 30,000 stars to magnitude 7.6, and 1,500 deep-sky targets — star clusters, nebulae, and galaxies — to search out among them.

Next up is the larger and deeper Sky Atlas 2000.0, plotting stars to magnitude 8.5; nearly three times as many, as well as many more deep-sky objects. It's currently out of print, but maybe you can find one used.

The next up, once you know your way around well, are the even larger Interstellarum Deep-Sky Atlas (with 201,000+ stars to magnitude 9.5 and 14,000 deep-sky objects selected to be detectable by eye in very large amateur telescopes), and Uranometria 2000.0 (332,000 stars to mag 9.75, and 10,300 deep-sky objects).

For the necessary tricks, read How to Use a Star Chart with a Telescope. It applies just as much to electronic charts on your phone or tablet — which many observers find handier and more versatile, if sometimes less well designed and contextualized.

You'll also want a good deep-sky guidebook. A beloved old classic is the three-volume Burnham's Celestial Handbook. It was my bedside reading for years. An impressive more modern one is the big Night Sky Observer's Guide set (2+ volumes) by Kepple and Sanner. The pinnacle for total astro-geeks is the new Annals of the Deep Sky series, currently at 11 volumes as it works its way forward through the constellations alphabetically. So far it's up to H.

Can computerized telescopes replace charts? Well, I used to say this:

"Not for beginners, I don't think, unless you prefer spending your time getting finicky technology to work rather than learning how to explore through the sky yourself. As Terence Dickinson and Alan Dyer say in their Backyard Astronomer's Guide, 'A full appreciation of the universe cannot come without developing the skills to find things in the sky and understanding how the sky works. This knowledge comes only by spending time under the stars with star maps in hand and a curious mind.' Without these, 'the sky never becomes a friendly place.' "

But things change. The technology has continued to improve and become more user-friendly — particularly with "plate solving" software that can now recognize any star field to determine exactly where the telescope is pointed — finally bypassing all aiming imperfections in the mount, tripod, gears, bearings and other mechanics, or in the user's skill in setting up.

The latest revolution is the rise of small, photography-only "smartscopes." These take advantage of not only today's pointing technology, but also the vastly better capabilities of imaging chips and image processing compared to the human retina and visual cortex. The most sophisticated image stacking and processing can come built right in. The result is decent deep-sky imaging from shockingly small units, relatively low priced. The image may be viewable on your phone or computer as it builds up in real time. Some can directly enable contributions to citizen-science projects.

Smartscopes are changing the hobby at the entry level. For more on this see Richard Wright's "The Rise of the Smart Telescopes" in the November 2025 Sky & Telescope. And read the magazine's review of this especially small one.

If you get a larger, more conventional computerized scope that you can look through, make sure that its drives can be disengaged so you can swing it around and point it readily by hand when you want to, rather than only slowly by the electric motors (which eat batteries).

Audio sky tour. Out under the evening sky with your
earbuds in place, listen to Kelly Beatty's monthly
podcast tour of the naked-eye heavens above. It's free.

"The dangers of not thinking clearly are much greater now than ever before. It's not that there's something new in our way of thinking, it's that credulous and confused thinking can be much more lethal in ways it was never before."
            — Carl Sagan, 1996, The Demon-Haunted World: Science as a Candle in the Dark

"Facts are stubborn things; and whatever may be our wishes, our inclinations, or the dictates of our passion, they cannot alter the state of facts and evidence."
            — John Adams, 1770, in the summation of his unpopular, but successful, defense of British soldiers in the Boston Massacre trial

"Truly, whoever can make you believe absurdities can make you commit atrocities."
            — Voltaire, 1765, Questions sur les miracles