■ Late these evenings as autumn approaches, Fomalhaut, the Autumn Star, makes its inevitable appearance above the southeast horizon. Its rising time will depend on where you live. But by 10 or 11 p.m. you should have no trouble identifying it sparkling low in the southeast if you have a good view in that direction. No other 1st-magnitude star is anywhere near there.

Hint: It's about two fists lower left of Saturn.


■ Another sign of the advancing season: Cassiopeia is high in the northeast, its W pattern tilting up. And below it, starry Perseus is reaching up.

The highest part of Perseus includes the wintry Double Cluster. To find it, look below the lowest two stars of the Cassiopeia W, by 1½ times the distance between them. You're looking for what seems like a small spot of enhanced Milky Way glow. Binoculars or a finderscope will help you detect the Double Cluster even through a fair amount of light pollution. In a telescope the pair are a glory: a distant twin city of stars.

■ The asteroid 4 Vesta is just past opposition and showing itself at a relatively bright magnitude 6.2 this week. It's in western Aquarius about 8° southeast of 3rd-magnitude Delta Capricorni, Saturn's near neighbor. Use binoculars or a telescope with the finder chart in the August Sky & Telescope, page 49 (or the less detailed chart at Observe Vesta — and own a piece of it, too.)

■ New Moon (exact at 4:17 a.m. on this date EDT).


■ The Sagittarius Teapot is still nearly on the meridian (due south) right after nightfall is complete. It's tilting to pour to the right. Explore with binoculars before moonlight returns later this week.

The Sagittarius Teapot deep-sky and surroundings.
On dark clear nights, the Large Sagittarius Star Cloud seems to emerge like steam from the spout of the Sagittarius Teapot.


■ Soon after sunset, like 20 minutes or so, start scanning for the super-thin crescent Moon quite low over the west horizon in bright twilight. Binoculars or a wide-field telescope may make the difference for spotting it if the air is not crystal clear.

Got the Moon? Then look about 6° below it for little Mercury heading down and away.


■ As twilight fades look low in the west for the crescent Moon, less thin and delicate than yesterday, with little Spica 4° or 5° to its left.

Some three fists to their upper right, Arcturus glimmers through the twilight.


■ Now the thickening Moon hangs upper left of Spica in the western twilight, by roughly a fist at arm's length.


■ The change of August to September means that Scorpius, which was the proud starring constellation of the south during the height of summer, now turns to lie horizontally in the southwest after nightfall is complete, preparing to bed down for the season.

The Moon, getting near first quarter, hangs to Scorpius's right.


■ Now the Moon, nearly first quarter, poses just to the right of the head of Scorpius after dusk as shown below. The star closest to the Moon there is Delta Scorpii, the brightest in the area after Antares.

Waxing Moon passing over Scorpius and Sagittarius, Sept 2-5, 2022
The waxing Moon after dusk steps across the southernmost constellations of the zodiac: Scorpius and then Sagittarius.

■ How soon after sunset can you see the big Summer Triangle? Face east and look way up. Vega, the Triangle's brightest star, is nearly at the zenith (for skywatchers at mid-northern latitudes). Deneb is the brightest a couple fists to Vega's east-northeast. Altair shines less high in the southeast, farther from Vega.

A winter preview: Step out before the first light of dawn this week, and the sky displays the same starry panorama it does at dinnertime around New Year's. Orion is striding up in the southeast, with Aldebaran and then the Pleiades high above it. Sirius sparkles far down below Orion. The Gemini twins are lying on their sides well up in the east, left of Orion.

And brilliant Mars, currently dominating the scene near Aldebaran as shown below, is no planetary anachronism in this preview. The doings of its retrograde loop in the next four months will keep it in the general vicinity of Aldebaran and make it even brighter than it is now.


■ First-quarter Moon (exact at 2:08 p.m. EDT). Nightfall in North America finds the Moon in the south-southwest a few degrees upper left of Antares, as shown above. The next-brightest star there is Delta Scorpii, 8° to the right of Antares.

■ Mars is just 4½° above Aldebaran in the dawn Sunday morning the 4th as shown below. This is essentially as close as they'll get; Mars passes widely north of Aldebaran this coming week.

Mars over Aldebaran at dawn, Sept 4, 2022
In early dawn, Mars in Taurus lords over Aldebaran and Orion.


This Week's Planet Roundup

Mercury is fading and sinking very low into the sunset glow. Early in the week, you can try scanning for it with binoculars or a wide-field telescope about 20 or 30 minutes after sunset. Look just above the horizon a little left of due west. Good luck.

Don't be misled if you sweep up sparkly Spica. It's some 20° to Mercury's upper left.

A super-thin crescent Moon hangs about 6° above Mercury in the twilight of August 29th.

Venus, magnitude –3.9 in Leo, rises about a half hour after dawn begins. As dawn brightens, look for it very low in the east.

Mars, magnitude –0.1 in Taurus, rises around 11 or midnight in the east-northeast. By early dawn it shines very high in the southeast. Mars is now three times as bright as similarly colored Aldebaran, magnitude +0.9, a little way below it.

Mars is 10 arcseconds in apparent diameter and growing. It'll be 17.2 arcseconds wide when closest to Earth on December 1st.

Jupiter rises due east in twilight. By dark it's glaring low at a bright magnitude –2.8. Jupiter stands highest in the south around 2 or 3 a.m. daylight-saving time, in an undistinguished area near the Pisces-Cetus border.

In a telescope Jupiter is 49 arcseconds wide, nearly its maximum possible! Even though it doesn't reach opposition until September 26th. That's because this year it's nearly at the perihelion of its 12-year orbit around the Sun.

Jupiter with Great Red Spot on the central meridian
Jupiter on August 13th, imaged by Christopher Go at 18:32 UT with the Great Red Spot nearly on Jupiter's central meridian (which was at System II longitude 20°). South is up here, to match the view in many telescopes. The Red Spot is almost completely surrounded by dark border material of the Red Spot Hollow. Just south of it are two small white ovals. The dark North Equatorial Belt is turbulent and chaotic on this side of the planet. At the time of this image the NEB displayed a tiny bright-white outbreak, a zone of rising thunderheads.

Saturn, magnitude +0.3 in western Capricornus, was at opposition August 14th. Now you can spot it in the southeast in late twilight. It's higher later in the evening and at its highest and best in the south around 11 or midnight. It sets around the beginning of dawn.

Saturn's rings appear roughly as wide, end to end, as Jupiter's globe. See the August Sky & Telescope, page 48.

Saturn with and without the Seeliger effect
Saturn on April 22, 2022, far from opposition (top) and on August 15, 2022, one day past opposition. Note the Seeliger effect: the brightening of the rings compared to the globe that happens for a few days around Saturn's oppositions. This occurs because dust particles in the rings preferentially backscatter light in the direction the light came from but Saturn's cloudtops don't. This same "opposition surge" occurs for Mars, the full Moon, and other objects with dusty surfaces. You can sometimes see it on dusty ground around the shadow of your head. In the case of Saturn's rings, this effect was first analyzed and described by Hugo von Seeliger in 1887.

Christopher Go took both images. South here is up. We have adjusted the originals to make the globes appear similar, to show the actual amount of the rings' brightening realistically. It's not dramatic but definitely noticeable in the eyepiece if you're a regular Saturn observer.

Uranus, magnitude 5.7 in Aries, is west of Mars before dawn.

Neptune, magnitude 7.8 at the Aquarius-Pisces border, rises in evening twilight west of Jupiter.

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. (Universal Time is also called UT, 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 an easy-to-use 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.

Once you get a telescope, to put it to good use you'll need a detailed, large-scale sky atlas (set of charts). The basic standard is the Pocket Sky Atlas (in either the original or Jumbo Edition), which shows stars to magnitude 7.6.

Pocket Sky Atlas cover, Jumbo edition
The Pocket Sky Atlas plots 30,796 stars to magnitude 7.6, and hundreds of telescopic galaxies, star clusters, and nebulae among them. Shown here is the Jumbo Edition, which is in hard covers and enlarged for easier reading outdoors by red flashlight. Sample charts. More about the current editions.

Next up is the larger and deeper Sky Atlas 2000.0, plotting stars to magnitude 8.5; nearly three times as many. The next up, once you know your way around, are the even larger Interstellarum atlas (stars to magnitude 9.5) or Uranometria 2000.0 (stars to magnitude 9.75). And be sure to read How to Use a Star Chart with a Telescope. It applies just as much to charts on your phone or tablet as to charts on paper.

You'll also want a good deep-sky guidebook. A beloved old classic is the three-volume Burnham's Celestial Handbook. An impressive more modern one is the big Night Sky Observer's Guide set (2+ volumes) by Kepple and Sanner.

Can a computerized telescope replace charts? Not for beginners, I don't think, and not on mounts and tripods that are less than top-quality mechanically, meaning heavy and expensive. And 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."

Audio sky tour. Out under the evening sky with your
earbuds in place, listen to Kelly Beatty's monthly
podcast tour of the 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

"Facts are stubborn things."
             John Adams, 1770



Image of Rod


August 26, 2022 at 6:02 am

For early risers I was out near 0540 EDT this morning. Mars in Taurus, lovely sight along with M45 and Aldebaran this morning. I could see A1 Tau (37 Tauri) star (magnitude 4.35) about 2-degrees 42 arcminutes from Mars position (Stellarium 0.22.2 angle mode). Omega Tau (Omega Tauri) magnitude 4.90, visible about 2-degrees 56 arcminute from Mars position in Taurus (Stellarium 0.22.2 angle mode). M45 using 10x50 binoculars a very nice view. Sunrise 0630 EDT. 0540 EDT, early morning twilight visible in east. The sky slowly brightening as sunrise approaches. Does the Sun move around the Earth causing sunrise or does the Earth spin on its axis? 🙂

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August 26, 2022 at 5:56 pm

Just a reminder that over the Labor Day weekend the Sun's position in the sky will be close to where it will be during the April 8 2024 total solar eclipse.

If you are planning to view the eclipse locally (not travel to the path of totality), you can use that weekend to try out good viewing sites, to both view the eclipse and to get nice backdrops for photo vistas.

This link provides the local circumstances for major cities in the U.S., Canada, and Mexico:

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August 27, 2022 at 11:51 pm

Some asteroid, Saturn, and Jupiter observing tonight. Observed 2145-2300 EDT. I used 10x50 binoculars with star hop 66 and 68 Aquarii, 47 Aquarii, and the double star 41 Aquarii to locate and view 4 Vesta asteroid this evening. 4 Vesta was located a bit more than 13 arcminute angular separation from 41 Aquarii double star. Using the 90-mm refractor at 71x, this was easy to see. 41 Aquarii double easy split and ~ 5 arcsecond angular separation. Other stars fainter some 8th to 11th apparent magnitude according to Stellarium and Starry Night within about 0.5-degree circle framed by 41 Aqr and 4 Vesta. The sight was lovely, a good photo opportunity. I enjoyed views of Saturn with the moons Titan and Rhea visible along with Cassini division. Later near 2300 EDT, Jupiter rose above a tree line. Jupiter showed many cloud bands, 3 Galilean moons on the right side, one on the left side. This was north up, mirror reverse view in the refractor telescope. A good evening out tracking down 4 Vesta asteroid, viewing Saturn with two moons apparent, and Jupiter with 4 Galilean moons and cloud bands. Vesta in retrograde loop in Aquarius moving towards Capricornus. site shows 4 Vesta at mv +6.1, Stellarium 5.7 and Starry Night 5.56 magnitude.

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mary beth

August 29, 2022 at 11:53 am

Hello everyone and Happy Late Summer! I have been enjoying everyone’s posts. We have had a cloudy August in Texas so not much to report other than being blessed to see the beautiful golden 3% crescent moon last night. I was not expecting clear skies or the ability to see the moon because of tree line. But the sky cleared in the golden hour, and the moon was positioned in between two very large trees allowing me a perfectly framed view of the moon. I guess it’s the start of the Harvest moon! Time flies especially this time of year!

Jupiter is stunning! Was so happy to see it too. I didn’t think it would be high enough so was thrilled when I saw it.

Hope everyone is doing well. School has started and things are back in place after summer break. I love this time of year!

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August 29, 2022 at 6:01 pm

mary beth, good observation 🙂 If you use binoculars like 8x50 or 10x50, you can watch 4 Vesta move westward (retrograde) towards Capricornus. 41 Aquarii double star is easy to see along with the asteroid and a position fix. Stellarium makes it easy to chart. You will need a telescope to split 41 Aquarii as a double star at 5 arcsecond separation. August for me has been pretty good observing. 01-Aug, 12-13 Aug, 24-Aug, and 26-27 Aug viewing. Plenty of lap swimming this summer too in various pools 🙂

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mary beth

August 31, 2022 at 7:10 pm

If we have clear skies in the next few evenings I will definitely do that, thank you! I went to the S&T page about it since you piqued my interest. I like the way you used Stellarium to find your targets. Such a great site.

I’m so glad you’ve had some clear skies because it seems like in the earlier part of the summer you were having lots of clouds. Great you’re keeping up with the swimming, I bet you really felt like swimming when you were here visiting in Texas and it was so hot!

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