This Week's Sky at a Glance, July 10 – 19

FRIDAY, JULY 10

■ In early dawn tomorrow the 11th, look east-northeast for the waning crescent Moon forming a diagonal line with Mars and Aldebaran under it, as shown below.

SATURDAY, JULY 11

■ The Big Dipper, high in the northwest as evening advances, is beginning to turn around to "scoop up water" through the hours and months to come.

■ And low in the north-northeast after dark, the upright W of Cassiopeia is slowly beginning to tilt and climb.

SUNDAY, JULY 12

■ Look low in the northwest or north at the end of these long summer twilights. Would you recognize noctilucent clouds if you saw them? They're the most astronomical of all cloud types, what with their extreme altitude and, sometimes, their formation on meteoric dust particles. They used to be rare, but they've become more common in recent years as Earth's atmosphere changes. See Bob King's Nights of Noctilucent Clouds.

MONDAY, JULY 13

■ You may already know about the Large Sagittarius Star Cloud, that rich puff of Milky Way just off the spout of the Sagittarius Teapot. This is our very partial view of the dense swarm of stars near the center of our galaxy some 25,000 light-years distant. (The Milky Way's exact center is hidden by dark dust clouds in the foreground.) It's not only the brightest, but the farthest part of the Milky Way that's visible to the naked eye.

And did you know about the little globular star cluster NGC6522 embedded in it? This dense, tiny cluster is just 0.6° northwest of 3rd-magnitude Gamma Sagittarii, the tip of the Teapot's spout. Both fit within the low-power view of most amateur telescopes. NCG 6522 is magnitude 8.5, but switch to higher power once you think you've found it because it's tiny and dense. See Matt Wedel's Binocular Highlight column and chart in the July Sky & Telescope, page 43.

If you find NGC 6522, try for the smaller, fainter globular NGC 6528 to its east by 0.4°, and north-northwest of Gamma Sagittarii by just 0.3°.

TUESDAY, JULY 14

■ One hour after sunset, as twilight is fading and the stars are coming out, you'll find the two brightest stars of summer, Vega and Arcturus, equally near the zenith: Vega toward the east, Arcturus toward the southwest (depending on your location).

■ New Moon (exact at 5:44 a.m. on this date EDT).

WEDNESDAY, JULY 15

■ Soon after nightfall, look due south for orange Antares on the meridian. Around and upper right of Antares are the other, whiter stars forming the distinctive pattern of upper Scorpius. The rest of the Scorpion runs down from Antares toward the horizon, then left.

Three doubles at the top of Scorpius. The head of Scorpius — a near-vertical row of three stars — stands upper right of Antares. The top star of the row is Beta (ß) Scorpii or Graffias: a fine double star for telescopes, separation 13 arcseconds, magnitudes 2.8 and 5.0. (They're unresolved in the photo below.)

Just 1° below Beta is the very wide naked-eye pair Omega¹ and Omega² Scorpii. They're 4th magnitude and ¼° apart. Binoculars show their slight color difference; they're spectral types B9 and G2.

Upper left of Beta by 1.6° is Nu Scorpii, separation 41 arcseconds, magnitudes 3.8 and 6.5. In fact it's a telescopic triple. High power in good seeing reveals Nu's brighter component itself to be a close binary, separation 2 arcseconds, magnitudes 4.0 and 5.3, aligned almost north-south.

THURSDAY, JULY 16

■ In twilight this evening, low in the west, catch the returning crescent Moon less than a fist to the lower right of Venus, as shown below. Hardly more than 1° from the Moon (depending on your location), look for vastly fainter Regulus.

FRIDAY, JULY 17

■ Now the crescent Moon shines less than a fist left of Venus at dusk, as shown above.

Although the Moon is a crescent, a telescope reveals Venus to be gibbous. Even though they stand in the same part of the sky. Why?

The Moon is closer to us than the Sun is, so we see more of the Moon's night side. Venus is on the far side of the Sun from us, so we see more of its daylit side.

SATURDAY, JULY 18

■ Starry Scorpius is sometimes called "the Orion of Summer" — for its brightness, its blue-white giant stars, and its prominent red supergiant (Antares in the case of Scorpius, Betelgeuse for Orion). But Scorpius passes a lot lower across the southern sky than Orion does, for those of us at mid-northern latitudes. That means it has only one really good evening month: July.

The rich area around the tail of Scorpius is now at its best low in the south right after night is fully dark, as shown below. Find about a fist and a half at arm's length lower left of Antares. Or, about a fist or less lower right of the spout of the Sagittarius Teapot. How high or low this whole scene will appears depends on how far north or south you live: the farther south, the higher.

SUNDAY, JULY 19

■ The eyes in the tail. Spot the two stars especially close together in Scorpius's tail, shown above. These are Shaula and Lesath, Lambda and Upsilon Scorpii, also known as the Cat's Eyes. They're unequal and canted at an angle; the cat has a bleary eye and is tilting his head to our right. They're magnitudes 1.6 and 2.6. Both are blue-white supergiants, 700 and 500 light years away, respectively. The fainter one, Lesath, is the nearer one.

Between the Cat's Eyes and the Teapot's spout are the open star clusters M7 and M6, speckle-splashes in binoculars. M7 is the bigger and brighter one; M6 is much less of a standout.

Also: A line through the Cat's Eyes points side-eye to the right (west) by nearly a fist toward Mu Scorpii, a much tighter pair known as the Little Cat's Eyes. They're oriented almost exactly the same way as Lambda and Upsilon, but they're only 0.1° apart, so they appear as a single dot on the chart above; bring binoculars. They too are not a true binary. They're 800 and 500 light-years away, and again the fainter one is nearer.

---

---

This Week's Planet Roundup

Mercury is buried in the glow of sunrise.

Venus shines brightly (magnitude –4.2) as the "Evening Star" low in the west in twilight. It's getting a little lower every week. It now sets around the end of twilight.

As twilight deepens, look for Regulus to Venus's lower right. It's only 1/180 as bright at magnitude +1.4, so bring those binoculars. On Friday July 10th they're still just 1.6° apart. But the gap between them widens fast, to 9° by Friday the 17th.

In a telescope, Venus is a brilliant little gibbous disk 63% sunlit and 18 arcseconds from pole to pole. Catch it as soon in the late afternoon or early dusk as you can, before it sinks low into worse atmospheric seeing.

Venus will remain in twilight view until the end of the summer, ever lower, enlarging while waning in phase.

Mars, magnitude +1.3 in Taurus, glows in the east in early dawn. Aldebaran, its near-twin in brightness and color, twinkles 6° to its lower right or right.

Mars is still on the far side of its orbit from us, so in a telescope it's only a tiny, fuzzy blob 4½° arcseconds wide.

Jupiter is buried deep in the sunset.

Saturn (magnitude +0.7, at the Pisces-Cetus border) rises in the east around midnight. Once it's up, find it below the Great Square of Pegasus. It's well placed for telescopic viewing high in the southeast before dawn. Saturn is the brightest thing in its dim area. Don't confuse it with Fomalhaut, its near-twin in brightness, twinkling four fists down to Saturn's lower right.

Late last fall Saturn's rings turned nearly edged-on to Earth and almost disappeared. Now the rings' inclination has widened back up to 9°.

Uranus (magnitude 5.8, in Taurus) hides in the distance 5° west of Mars.

Neptune (magnitude 7.9, at the Pisces/Cetus border) hides even more distantly 10° west of Saturn. You'll need detailed finder charts to distinguish Uranus and Neptune from background stars of similar brightness.

---

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

---

---