■ Full Moon tonight (exactly full at 5:59 a.m. Saturday morning EDT). The Moon rises in the east-southeast just after sunset.

As the stars come out, you can see that the Moon is between bright Jupiter a couple of fists to its left or lower left, dimmer Saturn farther to the Moon's upper right (out of the frame below), and Fomalhaut, twinkling down to the Moon's lower right. The Moon forms a roughly equilateral triangle with those last two.

The Harvest Moon turns waning gibbous as it passes Jupiter.
How did the Harvest Moon get its name? Supposedly, it's from the fact that at this time of year, the waning gibbous Moon after full keeps rising before the end of twilight for several days running (due to the low tilt of the ecliptic over the eastern horizon). This gave farmers in the busy harvest season extra light to work in their fields. Now, farm equipment comes with headlights.


■ The Moon, a day past full, rises in early twilight with Jupiter now shining just one fist or less to its left, as shown above.


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


■ The Moon now shines well to Jupiter's lower left in mid- to late evening.

Look less far to the Moon's left or upper left for the two or three brightest stars of Aries. They're lying more or less horizontally.


■ The stars say the season is changing: We've reached the time of year when, right at nightfall, Cassiopeia has climbed as high in the northeast as the Big Dipper has sunk in the northwest. Cas highlights the northern sky in early evening during the chilly fall-and-winter half of the year. The Big Dipper takes over for the mild evenings of spring and summer.

Almost midway between the two stands Polaris. It's currently a little above the midpoint between them.


■ Spot the Big Dipper scooping low in the northwest. Examine Mizar, the middle star of its bent handle. Can you see its tiny close companion Alcor? Since this is the time of year when Vega is crossing the zenith in early evening, it's also when Alcor stands straight over Mizar. Because a line from Mizar through Alcor always points to Vega.

■ As dusk turns to night, Arcturus twinkles due west. It's getting lower every week. From Arcturus, the narrow, kite-shaped pattern of Bootes extends upper right by a little more than two fists at arm's length. Farther off to the right in the northwest, the Big Dipper is turning more and more level.


■ The Great Square of Pegasus is climbing the eastern sky. Look for it above bright Jupiter and maybe a bit left. It's balancing on one corner, as it always does when we see it in either the east or the west. Only when the Great Square is very high and more or less south does is sit level like a box.

■ Late these nights, ever-brightening Mars dominates the eastern sky, well outshining Aldebaran to its right as shown below. In the small hours of the morning Betelgeuse, essentially the same color as Mars and Aldebaran, will come up farther below them. (The dates in the illustration consider midnight to be part of the evening date.)

Waning Moon passing Mars and Aldebaran, Sept 15-17, 2022
When the Moon is waning, the direction of sunlight gives its craters and mountains a different look than how we're usually used to seeing them: in the more convenient evening hours when the Moon is waxing. Mars now adds to the telescopic attraction. The later in the wee hours of the morning you look, the higher and telescopically sharper they'll be.


■ Now the late-rising Moon shines in line with Mars and Aldebaran to its right, as shown above. The Moon and Mars are about 4° or 5° apart as seen from the longitudes of the Americas. But this is still the closest pairing of the Moon and a bright planet visible in September from this part of the world.


■ Arcturus shines in the west these evenings after twilight fades out. About a half hour after nightfall is complete, brighter Jupiter shines at the same height in the east. How well can you time their exact balance?

Barely rising in the north-northeast when that happens is Capella (depending on your latitude; the farther north you are the higher it will be.) Capella and Arcturus are both magnitude 0.

Later in the evening, Arcturus and Capella shine at the same height. Again, the time of this will depend on both your latitude and longitude.

Watch for when it happens. Then turn and look low in the south-southeast. There will be 1st-magnitude Fomalhaut at about the same height too — exactly so if you're at latitude 43° north (Boston, Buffalo, Milwaukee, Boise, Eugene). Seen from south of that latitude, Fomalhaut will appear higher than Capella and Arcturus are. Seen from north of there, it will be lower.

■ Neptune is at opposition. It's magnitude 7.8 in eastern Aquarius. Equally bright (or faint) this week is the asteroid 3 Juno about 10° to Neptune's west. Using a telescope or large binoculars, find them both in late evening using the article and charts in the September Sky & Telescope, page 49.

And some 20° west-southwest of Juno, brighter 4 Vesta shines on at about magnitude 6.3. Use the finder chart in the August Sky & Telescope, page 49.

■ Last-quarter Moon (exact at 5:52 p.m. EDT). The Moon rises around 11 or midnight in the northeast, two fists lower right of Capella.

Once the Moon is well up, you can see that it makes a nearly equilateral triangle, 7° on a side, with the two horn-tip stars of Taurus: Beta and Zeta Tauri. They're to its upper right and right, respectively.


This Week's Planet Roundup

Mercury is hidden in the glare of the Sun.

Venus, magnitude –3.9, rises in mid-dawn about 45 minutes before sunrise. As dawn brightens, look for Venus very low in the east. How near to sunrise can you still hold it in view?

Mars, magnitude –0.3 in Taurus, clears the east-northeast horizon around 11 p.m. and gains altitude for the rest of the night. It's more than three times as bright as Mars-colored Aldebaran, magnitude +0.9, sparkling to the right or lower right of it. Look for the Pleiades farther above them.

By the beginning of dawn this array is very high in the south-southeast. This the best time to examine Mars in a telescope: when we see it highest through the thinnest, steadiest air. Mars is nearly 11 arcseconds in diameter and growing. It'll appear 17.2 arcseconds across when closest to Earth on December 1st.

Jupiter, a bright magnitude –2.9, glares very low due east by late twilight. After dark it dominates the low east, then the higher southeast, in an otherwise bland area at the Pisces-Cetus border. It stands highest in the south around 1 or 2 a.m. daylight-saving time.

In a telescope Jupiter is 49 to 50 arcseconds wide across its equator, nearly its maximum possible, as it nears its September 26th opposition. Jupiter this year is close to the perihelion of its 12-year orbit around the Sun.

Jupiter with Great Red Spot on the central meridian, Aug 13, 2022
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 was almost completely surrounded by dark border material of the Red Spot Hollow. Below, the dark North Equatorial Belt was turbulent and chaotic.

Saturn, magnitude +0.4 in eastern Capricornus, is a month past opposition. So as twilight fades you can spot it fairly well up in the southeast. It's at its highest and best in the south around 10 or 11 p.m.

Saturn imaged by Christopher Go on Aug 26, 2022
Saturn imaged by Christopher Go on August 26th. South is up. Saturn was just two weeks past opposition, but that was enough for the shadow of the globe to start showing on the rings behind it: just off the globe's lower-left limb as seen here. Watch the shadow widen in the coming weeks and months.

The gray band seen on the globe along the inner edge of the rings is not a shadow but the dim, semi-transparent C ring itself.

Uranus, magnitude 5.7 in Aries, is west of Mars late at night.

Neptune, magnitude 7.8 at the Aquarius-Pisces border, is 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


September 9, 2022 at 6:10 am

Last night (08-Sep) I enjoyed some time under Cygnus. [Observed 2000-2130 EDT. Sunset 1926 EDT. Full Moon 10-Sep-2022 0959 UT. The waxing gibbous Moon ascending in Aquarius, brightening the night sky the higher it ascended. Near 2100 EDT, Jupiter was visible ascending in Pisces behind some trees in the ESE. Jupiter ascending sounds like a movie 🙂 Using 10x50 binoculars, I located 61 Cygni double star and used the Telrad to target it. I observed 61 Cygni double star at 71x using TeleVue 14-mm Delos with my 90-mm refractor telescope. Easy split and lovely color seeing two stars spectral class K, both close to slight orange-yellow color, see I found various reports indicating their angular separation some 24 to 30.7 arcseconds, site shows 28.7 arcseconds. Using 3.495 pc that is about 84 AU separation as a binary system if 24 arcsecond separation or ~ 100 AU using 28.7 arcsecond. The telescope FOV just a bit larger than 1-degree was very enjoyable. Stars in the 8th-11th magnitude visible all around 61 Cygni double star. I enjoyed views of Albireo as a double star too in Cygnus. Delightful golden-yellow with blue color combination. Stellarium 0.22.2 indicates angular separation 65.6 arcseconds and 118.2 pc so about 7754 AU separation. Wikipedia reports 35 arcsecond angular separation for Albireo, and reports 34.7 arcsecond. Using 35 arcsecond 118.2 pc, both stars could be separated by about 4137 AU. In the eyepiece view, both 61 Cygni and Albireo appeared with an angular separation that looked very similar as double stars. Stellarium 0.22.2 reported 61 Cygni double as 37 or close to 38 arcseconds angular separation. A lovely evening in Cygnus viewing an historic star, 61 Cygni and Albireo double star. Clear skies and temperature 17C.]

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Image of Rod


September 14, 2022 at 6:20 am

Some time looking at Saturn and Jupiter last night 🙂 Observed 2045-2200 EDT. Waning gibbous Moon rise in Aries 2112 EDT. Last Quarter Moon 17-Sep-2022 2152 UT/1752 EDT. Near 2135 EDT, I viewed the beautiful Moon rising, a tint of orange yellow with altocumulus clouds moving in from the west. I was along the road by a large horse farm and fields. These clouds moving in from the west obscured my telescope views of Saturn and Jupiter, so I packed it up near 2200 EDT. However, using TeleVue 9-mm Nagler with TeleVue 1.8x Barlow lens and my 90-mm refractor telescope, I enjoyed some good views of Saturn at 200x. Cloud banding in the north region visible, Cassini division, hint of shadow on the rings, and Titan quite easy to see. I viewed Jupiter at 200x too. 4 Galilean moons visible, two on each side along with cloud banding. I switched to TeleVue 14-mm Delos for 71x views of Jupiter and Saturn. Very good until the clouds started moving across the sky, blocking out both planets and only sometimes visible between cloud breaks. Overall, a good evening viewing the Moon rise with unaided eyes, Jupiter and Saturn at 71x to 200x using the telescope.

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Image of Tom Hoffelder

Tom Hoffelder

September 14, 2022 at 1:48 pm

I check Sky at a Glance every Friday, mostly for the images because that tells me what might be of interest for naked eye viewing. Today I checked back for the midnight moon images, and was somewhat confused when I went to other sources to get altitudes for my location of Moon/Mars when closest. The image shows the date as the 16th, but since midnight is 00:00, it seems it should be the 17th. I am easily confused so maybe it is just me?

I would also like to mention that not giving an altitude for objects near the horizon could be confusing for the inexperienced. I live in southern Maine and have friends in central Florida, so I like to check to see what the difference in altitude can be. For the Moon/Mars on the 17th at midnight, the altitude is 16 deg for me but only 4 deg in central Florida. Sometime in the past, the altitude of objects was given, but perhaps that was ended because the altitude was only for a specific latitude which would make it necessary to explain that?

Thanks for taking some time to read my comment,
Tom Hoffelder
Norway Maine

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Image of Rod


September 14, 2022 at 4:24 pm

Tom Hoffelder, good note and comment. I noticed the difference in viewing Polaris from where I am in MD and back in early August when I viewed from East Texas near 33-deg latitude. Lower elevation or altitude for Polaris, higher for Scorpius and Sagittarius constellations. When I plan my telescope observing periods I use Virtual Moon Atlas, Stellarium 0.22.2, and Starry Night Pro Plus 8. Those apps quickly show the altitude and azimuth settings for various targets in the sky based upon your geolocation used along with rise, transit, and set times. Here is to clear skies for the Fall 🙂

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