The skies of August present a 14% partial solar eclipse, a 96% partial lunar eclipse, and a favorable peak of the annual Perseid meteor shower. We will also see the earliest-setting first quarter Moon, the waning crescent Moon occult the Pleiades, and Jupiter returning to the morning sky.
The Sun
The last 8:00pm sunset of 2026 is on the 4th. We’ll see earlier sunsets until May 17, 2027.
After crossing through Cancer for the past 21 days, the Sun begins a 37-day trek through Leo on the 10th.
The Moon joins the Sun on the afternoon of the 12th, as Lunation 1282 starts with a solar eclipse. The line of totality extends from northeastern Greenland, skirts western Iceland, southward through the North Atlantic, and ending in northern Spain.
While the best show is on the opposite side of the ocean, New England gets to see a partial eclipse on a Wednesday afternoon. There is no safe time to look directly at the Sun, so this eclipse is best viewed by means of a simple pinhole projector. Any opaque material with a small, clean hole (about 2-5cm, or ⅛-¼ inch) punched through it will project a distinct image of the Sun on any smooth surface.
Over Rhode Island, the partial eclipse begins at 1:03pm, and reaches maximum at 1:55pm, with 24.7% of the diameter of the Sun and 14.4% of the area of the solar disk occluded by the Moon. Even if the skies are 100% clear, this will not be enough obscuration to give any indication that it is not an ordinary sunny day; the sky will not appear any dimmer, and only the shadow projects should give any indication that there is a partial eclipse in progress.
The eclipse ends at 2:45pm. After the August 12 eclipse, our next solar eclipse will be a 9% partially eclipsed Sun on January 26, 2028.
Following August 12th, the next solar eclipse experienced here in Rhode Island will be on Jan 26, 2028, when just 3% of the Sun will be obscured.
Sometime during August you’ll start to notice that the Sun rises noticeably later, sets noticeably earlier, and the midday shadows get noticeably longer than during the past several weeks. On the 19th, the declination of the Sun is one quarter away from June solstice (+23.44°) to winter solstice (-23.44°), giving us our clearest indication yet that the summer season is coming to an end.
The 20th sees the last sunset in the 6:00am hour until April 19.
The Moon
On the 2nd, the 79.8% waning gibbous Moon is 3.0° north-northwest of Neptune, and the following night is 5.7° north of Saturn.
The 70.9% waning gibbous Moon spends the evening of the 3rd-4th with Saturn, appearing 5.7° north of the ringed planet just after the pair rises.
Last quarter Moon is at 10:21pm on the 5th, in Aries.
Just past Moonrise on the 6th, the 36.1% waning crescent occults the Pleiades, beginning at 12:26am on the 7th, and ending at 2:08am.
The 15.3% waning crescent Moon is 3.8° north-northeast of Mars on the 9th.
The Moon is new on the 12th, bringing the partial solar eclipse.
The beautiful Earthshone crescent Moon will be 4.3° west of Venus on the 15th. The following night, the 21.1% illuminated crescent is 8.6° to the southeast of Venus, the pair being nearly parallel to the horizon during evening twilight.
First quarter Moon is at 10:46pm on the 19th, in Libra. Setting at 10:49pm that evening, this is the earliest-setting first quarter Moon of 2026 due to its southerly declination. It is also notable how far south of west it sets.
On the 20th, the 59.0% waxing gibbous Moon shines with Antares, appearing just 2.0° southwest of the red supergiant star marking the heart of Scorpius
The full Sturgeon Moon comes on the evening of the 27th-28th, bringing with it this month’s most notable astronomical event, a partial lunar eclipse with a deep 96% obscuration.
The penumbral eclipse begins at 9:23pm, and the more visible umbral eclipse begins at 10:33pm. Maximum eclipse, when 96% of the Moon’s diameter falls under the umbral shadow, occurs at 12 minutes past midnight on the 29th. The partial umbral eclipse ends at 1:23am, and the penumbral eclipse ends at 3:01am.
Our next lunar eclipse after this month will be a penumbral eclipse early in the evening of February 20, 2027.
The 90.6% waning gibbous Moon is 5.2° north-northwest of Saturn on the 30th.
The Planets
Mercury
Mercury is at its best in the morning sky during early August, rising about 90 minutes before sunrise, in Gemini. It is at greatest elongation, 19.5° from the Sun, on the 2nd. On the 5th, it is 50% illuminated, and moves into its waxing gibbous phase afterwards.
The 2.4% illuminated waning crescent Moon is 2.0° northwest of Mercury on the 11th. The view will be best enjoyed with binoculars or a small telescope. Look for the pair directly below Castor and Pollux, rising out of the east-northeast.
As Mercury gets lower each morning, observing it against the backdrop of stars becomes more difficult, but users of medium-aperture telescopes may spot the stars of the Beehive Cluster, M44, just above Mercury on the 14th.
The next morning, the 15th, finds Mercury just 0.5° north of Jupiter.
From the 17th, Mercury rises less than an hour before sunrise and becomes more difficult to observe. It reaches superior conjunction on the 27th.
Venus
Venus enters Virgo on the 1st, and will remain within the celestial maiden on throughout the remainder of its 2026 evening apparition. It moves south of the celestial equator on the 5th.
The brilliant planet is 50% illuminated on the 12th, appearing in its half-Moon phase. It then progresses through its waning crescent phase as it gets closer to Earth.
Venus is at greatest elongation on the 15th, at 45.9° east of the Sun. While this is the point of its maximum angular separation from the Sun in our sky, you may notice that it seems to be much lower in the sky, and sets earlier than it did in early June, when it set around 11:00pm. This is because the ecliptic intersects the western horizon at its shallowest angle this time of year at sunset, which places the Moon and planets, which travel close to this path, much lower in the sky than during spring, when the ecliptic angle is close to perpendicular with the western horizon. Venus will remain in our evening sky for a few more weeks, but will continue to set earlier on successive nights until it drops out of view at the beginning of October.
The 13.0% waxing crescent Moon joins Venus on the 15th, appearing 4.2° west of the brilliant, magnitude -4-4 planet.
On the 16th, the Moon is 8.7° east-southeast of Venus, nearly parallel to the horizon.
Moving eastward approximately 0.9° per day, Venus approaches Spica, the brightest star in Virgo, through the final days of August, appearing just 1.4° west-southwest of the star on the 31st.
Mars
Mars is moving eastward through Taurus in the morning sky. On the 1st, the Red Planet is within 1.5° north of the Crab Nebula, M1, a supernova remnant enveloping a pulsar, a fast-rotating ultra-dense collapsed core of the massive star that created it about 1,000 years ago. Low magnification in a small to medium aperture telescope will reveal both objects within the same field of view. The Crab Nebula, at 6,500 light years, is over 200 million times as distant as Mars, which is 16.8 light minutes from us.
On the 5th, Mars bisects the line connecting Capella and Betelgeuse. For the next few days, it travels with dwarf planet Ceres, the two planetary bodies separated by just 1.4° on the 9th.
Mars crosses into Gemini on the 12th, when it can be seen just ⅓ ° north of NGC 2129.
Mars is 1/2° south of the more prominent open cluster M35 on the 15th.
By the end of August, Mars will grow to 5 arcseconds, and brighten to magnitude 1.2, equally as bright as Pollux, the star it appears to be approaching.
Jupiter
Jupiter returns to the morning sky from the far side of the Sun in August, but remains difficult to observe until mid-month, when it is joined by Mercury, about the width of the Moon to its north, on the 15th.
The giant planet rises before the onset of astronomical twilight for the first time on the 25th, and by the end of August, it rises two full hours before sunrise.
Saturn
Straddling the border of Pisces and Cetus, Saturn is readily visible in the evening sky during August.
After the equatorial plane crossing of 2025, Saturn’s rings are now tilted by about 11°, and the shadow cast by the planet’s oblate globe on the rings is quite pronounced.
The 70.9% waning gibbous Moon is 5.7° north of Saturn on the 3rd.
Saturn rises before 9:00pm by the end of August.
Uranus
Uranus is in the morning sky, and is easy to locate with binoculars between the Pleiades and Hyades clusters in Taurus. Once the prominent pair of clusters are well above the horizon, draw a line from Atlas (27 Tauri), the southeasternmost of the bright members of the Pleiades, towards Aldebaran. About ⅓ of the way to the brightest star of the bull, you’ll encounter 37 Tauri, a magnitude 4.4 star that is paired with 5.9 magnitude 37 Tauri just ⅙° in the same direction of Aldebaran. Note that this star is about the same brightness as Uranus. Continue to follow this line 2.1° towards the south-southeast, in the direction of Aldebaran, and you will find the blue-green Uranus.
Uranus rises before midnight beginning on the 16th, becoming an evening planet.
The seventh planet is at quadrature on the 28th.
Neptune
Neptune is an evening planet, located about 10.5° west-southwest of Saturn, in Pisces. It rises about 45 minutes before Saturn, and is best seen after midnight when it gains sufficient elevation to be above much of any obscuring haze.
Use the 79.8% waning gibbous Moon to locate our most distant planet on the 2nd, when it will be 3.2° north-northwest of Neptune. The brightness of the Moon will probably make it difficult to see Neptune if using binoculars, so a small telescope with a low power, wide field of view, is recommended to see the pair.
Beginning the second week of the month, when the Moon is out of the way, draw a line south from Alpheratz (α Andromedae) through Algenib (γ Pegasi), extending the eastern edge of the Great Square of Pegasus by about double its length. You will see a 0.3° by 0.9° quadrilateral of 6th and 7th magnitude stars, with its shorter segments roughly parallel to each other. Just under a degree to the south-southeast of the quadrilateral will be a 0.5° right triangle of 7th-8th magnitude stars, of similar brightness to our target. The two stars at the base of the triangle, extended less than ¾ ° to the west-southwest, point directly towards bluish Neptune.
The farthest planet is moving west-southwestward at 1 arcminute per day.
Minor Planets
August is a great time to locate Ceres, as the dwarf planet is moving eastward and passes close to some of the more easily recognizable stars of Taurus and Gemini. Since it passed within ¼° of the Crab Nebula in late July, it is still located within a small telescope field of view of both the supernova remnant, and Tianguan (zeta Tauri) during early August, starting the month just 0.9° north-northeast of the star, and 1.1° east of the nebula. Once you spot the magnitude 9.0 object, you can track its movement eastward about 22 arcminutes per day.
As Ceres moves out of range of Tianguan, it is joined by Mars, which is moving eastward at a faster rate than Ceres due to its closer orbit. Mars is just 1.4° north of the dwarf planet on the 10th, placing the pair within a small telescope’s field of view. While they appear close in our sky, Ceres is 1.67 times more distant than Mars, at 3.277 au and 1.957 au, respectively.
On the 23rd, Ceres passes just 6 arcminutes north of magnitude 3.3 Propus (η Geminorum). A keen-eyed observer using high magnification with a large telescope may be able to detect the motion of Ceres relative to Propus, as the dwarf planet is moving about 1 arcsecond per minute.
On the 29th, Ceres is 15 arcminutes east-northeast of magnitude 2.9 Tejat (μ Geminorum).
Pluto
Pluto, shining at magnitude 14.5, is well placed in the evening sky in southwestern Capricornus. You can find it 4.5° west-northwest of ψ Capricornum. Visual observers with telescopes of at least 12 inches of aperture on a dark and transparent night should have no difficulty picking up the dwarf planet at a distance of 34.6 au, but it should also be easy to acquire using the myriad of smart scopes in use.
Pallas
2 Pallas is in Cetus, and reaches its stationary position on the 13th.
Juno
3 Juno, which was at opposition in late July, remains well-placed in Aquila. Shining at magnitude 9.1, the 254-kilometer asteroid begins the month 5.0° south-southwest of θ Aquilae, and moves southwestward at 13 arcminutes per day. On the 15th-16th, it is just 1.0° northwest of 57 Aquilae, a double star with magnitude 5.7 and 6.4 components separated by 36.3 arcseconds (#86 on the Astronomical League’s Double Star Observing Program).
Vesta
Vests is located within the same region of sky as Pallas, in Cetus, just south of the southeastern Pisces border.
To locate Vesta, start at magnitude 4.1 Alrescha (α Piscium), a double star with a very tight 1.9 arcsecond separation, and #7 on the Astronomical League’s Double Star Observing Program. From Alrescha, move westward 2.2° to magnitude 4.6 ξ Piscium. Throughout August, Vesta remains within 3° of ξ as it arcs westward, then southward as it moves towards its stationary point on the 25th, then proceeds into retrograde motion.
The large asteroid brightens from magnitude 7.5 to 7.1 during August, placing it within easy reach of binoculars.
During the first third of the month, track Vesta by looking for an uneven zigzag of four 7th and 8th magnitude stars that extend north-south, are about 1.2° in length, and are positioned 2.5° southwest of ξ. These stars are, from north to south, HD 11088, HD 10930, HD 11028, and HD 10955. The two “zig” pairs point roughly back towards ξ. With these stars visible in your field of view, track Vesta as it moves to the north of this asterism.
On the 7th, Vesta lies almost directly in line between the top pair and ξ. On the 13th, it is directly between HD 11088 and HR 560, a 6th magnitude star 1.5° south-southeast of ξ. From then on, it will be easier to track the brightening asteroid with respect to HR 560.
Vesta is stationary on the 25th, at which point it is moving about 5 arcminutes per day away from HR 560.
Distant dwarf planet Eris, at a staggering 95.0 au, nearly three times the distance to Pluto, is just a few degrees southeast of Vesta. Beyond the reach of typical smart scopes, it will require more substantial aperture and image processing capabilities to detect its magnitude 18.5 glow, 33,000 times dimmer than Vesta.
Vesta and Eris are separated by 1.7° on the 8th.
Comets
Comet 10P/Tempel 2 is a midnight comet in August. Anticipated to shine as bright as 9th magnitude, the comet is at perihelion on the 1st, at 1.417 au, and closest to Earth on the 4th, at 0.414 au. Tempel 2 is in Pisces Austrinus, 11° west of Fomalhaut (α Piscis Austrini), and moving southeastward at about 0.4° per day during mid-August.
Meteor Showers
While the low-rate alpha Capricornids and delta Aquariids remain active into August, this month is best known for the Perseids, which is generally one of the more productive meteor showers of the year. The Perseids peak on the 12th-13th, which this year coincides with a new Moon, promising the best conditions, barring weather, for seeing up to 50 meteors per hour.
The radiant is circumpolar, so observers can expect to see these remnants of periodic comet 109P/Swift-Tuttle streak through the atmosphere at 59 km/s throughout all hours of darkness.
The Perseids have also been known to produce dazzling displays in the days leading up to the peak, so keep a lookout, not just on the 12th-13th, but all week.
Stars & Beyond
During the month of August, the center of the Milky Way stands prominently above the southern horizon at nightfall, providing observers with access to some of the sky’s best sights without the need to stay into the long hours of the night. And while the tree frogs and fireflies may have subsided, our nights are ever lively with the chorus of crickets and katydids to keep us company.
The second and third weekends of August and the week in between provide the darkest sky conditions, so be sure to plan at least one outing during these weeks.
If your observing site affords a view very low to the south, try to find one of the most southern Caldwell objects available in our Rhode Island skies, which will also take you into a constellation you’ve probably never visited before.
The Caldwell list, compiled by Sir Patrick Moore in 1995 and named for his full last name Caldwell-Moore to avoid conflicting with the Messier (M) catalog, the Caldwell list is ordered by declination from north to south, with object #81 at declination -48.42° being the most southerly object theoretically visible from the latitude of Seagrave Memorial Observatory (41,845°N).
Caldwell 78 (NGC 6541), a globular cluster at declination -43° 42’, isn’t quite a horizon-hugger, but it does culminate at 4.6° elevation, so it should be fairly easy to gain access to with a rich-field telescope. Its magnitude of 6.6 is extincted by a minimum of 1.4 magnitudes under ideal conditions due to airmass, so tracking it down with binoculars that aren’t of the giant variety could pose a significant challenge.
Locating the cluster is quite easy: When the “spout” of the teapot asterism of Sagittarius is close to the meridian, look towards the pair of stars marking the stinger of the scorpion, Shaula (λ Scorpii) and Lesath (υ Scorpii). Start at Shaula, the brighter one, then follow the line of stars to the southeast through κ and ι1 Scorpii. Continue this line 5.2° to the southeast, and C78 should present itself readily in a small telescope. For another point of reference, your target is just a fraction of a degree farther south than the southernmost stars of the scorpion. Use Sargas (θ Scorpii) 5.6° to the west as reference.
Located 22,000 light years from our solar system, C78 is a Shapley-Sawyer Class III, indicating that the 12.9 billion-year-old cluster of approximately 150,000 stars has a relatively dense core. At a more northerly declination, this cluster would certainly be a seasonal favorite like M15 and M92.
As you jumped from ι1 Scorpii to C78, you may not have realized that you crossed the constellation border into Corona Australis, the southern crown, a destination your telescope likely hasn’t visited before.
Corona Australis is a dim constellation bordered to the north and east by Sagittarius, and to the west by Scorpius. Its southernmost border, touching the constellations Telescopium and Ara, is a continuation of the southern border of Scorpius, and its northern border is at the same declination of the scorpion’s stinger stars Shaula (λ Scorpii) and Lesath (υ Scorpii).
Ranked ninth smallest in total area, Corona Australis contains no stars brighter than magnitude 4.1, and its 5-degree arc of stars passes by, largely unnoticed to northern hemisphere observers, a few degrees below the familiar teapot asterism of Sagittarius.
C78 is the brightest and most notable deep-sky object within the constellation.
If you succeed at observing C78 and are looking for a deeper challenge, Caldwell 79 (NGC 3201), a globular cluster in Vela that lies about 3° farther south than C78, is waiting for you next spring. It is best visible at the same time as the culmination of Regulus. But if you’re looking to continue your summer globular cluster adventure, turn 20° north, and slightly east, of C78, just 2.4° northeast of Kaus Borealis, the star marking the top of the teapot asterism, to find the large globular M22. At about half the distance of C78, and only about half as populous, M22’s brightest stars shine at magnitude 11, and it covers an area of sky about as large as the full Moon, so it is quite a treat to explore with small telescopes.
Have you taken any memorable adventures into lesser-known constellations? What are some of your favorite ones to explore?
