Category Archives: Skywatch Line

This is the Dudley Observatory Skywatch Line for Wednesday, November 25th, and Thursday, November 26th, written by Louis Suarato.

The 82% illuminated, waxing gibbous Moon rises at 2:30 p.m., Wednesday in the constellation Pisces, where it will be about 5 degrees below Mars, and trails the red planet across the sky. The Moon reaches apogee, its farthest distance from Earth during this lunar cycle, at 7:29 p.m., Thursday, at the distance of 252,211 miles, when it will join Mars in the constellation Pisces. Pisces is also the home of Messier deep sky object M74. M74 is a spiral galaxy about 32 million light-years from Earth. It is distinguished by two clearly defined spiral arms. Estimated to be 13.2 billion years old, M74 contains more than 100 billion stars. Also known as the Phantom Galaxy, for its dim surface brightness, the second lowest of all Messier objects, M74 is better seen on a moonless night with larger telescopes. This face-on galaxy was discovered by Pierre Mechain in 1780. Look for this galaxy 1.5 degrees east-northeast of the star Eta Piscium. Eta Piscium is halfway up the left side of the “V” that forms Pisces. On Wednesday and Thursday nights, M74 will be about 20 degrees to the left of Mars.

The second conjunction of the night is comprised of Saturn and Jupiter as they continue to move together and near their closest approach on December 21st. The two planets, now 3 degrees apart, emerge about 20 degrees above the south-southwestern horizon after sunset. Venus rises in Virgo at 4:30 a.m. Thursday. Venus is currently 88% illuminated as its elongation from the Sun decreases. Mercury is too close to the glare of the Sun to observe. Venus and Mercury are currently on the opposite side of the Sun from Earth.

Comet C/2020 S3 (Erasmus) has replaced Comet C/2020 M3 (ATLAS) as the brightest comet in the sky. Comet Erasmus is headed toward the Sun for its closest approach on December 12th, when it will be inside the orbit of Mercury. Discovered on September 17, 2020 by South African astronomer Nicolas Erasmus, this comet is estimated to have a 2,000 year orbit around the Sun. Comet Erasmus continues to brighten as it approaches the Sun, and is currently 7th magnitude. It is expected to reach 5th magnitude as it reaches perihelion. To locate the comet, first find Venus in the pre-dawn sky. Venus is in Virgo, and the constellation to its right is Hydra. The comet is 13 degrees to the lower right of Venus, in Hydra.

This is the Dudley Observatory Skywatch Line for Monday and Tuesday November 23rd and 24th, written by Joe Slomka.

The Sun sets at 4:26 PM; night falls at 6:06. Dawn breaks at 5:19 AM and ends with sunrise at 6:59.

Monday’s Moon rises at 1:47 PM in Aquarius, appearing 67% illuminated and sets at 1:08 AM, Tuesday. Tuesday, the Moon rises in Pisces at 2:09 PM, 41° high at 7 PM, appears 76% lit and sets at 2:08 AM, Wednesday.

Sagittarius continues to accommodate Pluto, Jupiter and Saturn. Dwarf Planet Pluto, 2°from Jupiter, is the first to rise at 10:53 AM, glowing with 14th magnitude, appearing as a tiny dot and sets at 7:50 PM. Jupiter rises next at 10:55 AM, glowing with minus 2nd magnitude, appearing 35 arc-seconds in size and sets at 8:02 PM. Saturn, 3° removed from Jupiter, rises at 11:05 AM, shines with zero magnitude, 15 arc-seconds wide, and sets at 8:17 PM. Jupiter relentlessly closes in on Saturn in preparation for their historic conjunction on December 21.

Mars resumes prograde (eastward) motion, rising in Pisces at 2:19 PM, gleaming with minus 1st magnitude, sized 15 arc-seconds, best observed at 8:40 PM and sets at 3:03 AM. Sharing Pisces, the Red Planet hovers 12° above the Moon on Tuesday night and 5° on Wednesday evening.

Neptune rises in Aquarius at 1:21 PM, glimmering with 8th magnitude, 2 arc-seconds small, best observed at 6:59 PM and sets at 1:21 AM. Uranus, rising at 3:12 PM in Aries, is brighter with 5th magnitude, a bit larger with 3 arc-seconds, best seen at 10:02 PM and sets at 4:57 AM. Neptune shares Aquarius with the Dwarf Planet 1Ceres. Ceres lies about 18° below Neptune and the Moon. Ceres rises at 1:37 PM, highest at 6:16 PM and sets at 10:55 PM. While Uranus is naked eye visible, Pluto, Neptune and 1Ceres are not. Beginners should obtain star charts from astronomy websites or magazines to assist in finding these distant and small members of our Solar System.

Ceres was the first asteroid discovered in the “Asteroid Belt.” It was discovered on Jan 1, 1800. Ceres was the goddess of agriculture and taught humans to grow grain. Ceres orbits the Sun about midway between Jupiter and Mars. It is the largest asteroid, about 600 miles across.

There is a lot of confusion about asteroids. The “asteroid belt” is usually pictured in movies as an almost solid ribbon of huge rocks. Actually, there are many thousands of miles between rocks of varying sizes. Scientists think they know the composition of some asteroids, from meteorites. Recently, Japanese spacecraft Hayabusa visited the asteroid Ryugu and NASA probe OSIRUS-REX called on asteroid Bennu; both explored and sampled the soil and are returning to Earth with samples. Several other missions are in various stages of development.

This is Dudley Observatory’s Skywatch Line for Friday, November 20, through Sunday, November 22, written by Sam Salem.

On Friday, Sun rises at 6:54am and sets at 4:28pm; Moon rises at 12:21pm and sets at 9:56pm. Moon sits in the middle of constellation Capricornus the Sea Goat, east of constellation Sagittarius and planets Jupiter and Saturn, on Friday.

The Moon completes the first quarter of its orbit around Earth at 11:45pm on Saturday. At that time, the relative positions of the Earth, Sun, and Moon will cause us to see Moon half-illuminated, on its eastern side. At first quarter, the Moon rises around noon and sets around midnight. The evenings surrounding first quarter are the best for seeing the lunar terrain when it is dramatically lit by low-angled sunlight. The small, round Mare Crisium, as well as Mare Fecunditatis and Mare Nectaris are easily visible on the Moon’s face. Through a telescope, look for the crater Theophilus, which has a prominent central mountain comprising three peaks that rise just over a mile above the crater floor. On Friday night, the crater should appear in sharp relief just to the right of the terminator, the line that divides lunar night from. Use a lunar map to help you identify the Moon features.

As dawn brightens Mercury is still nicely visible. If you have a low view to the east-southeast, look for Mercury lower left of Venus. Next week it will descend from sight down to the dawn horizon. The 3rd-magnitude star sitting about 1 degree to Mercury’s right is Alpha Librae. Look for Beta Librae farther off to the left.

On Sunday night, use the Moon to find the star Fomalhaut in the constellation Piscis Austrinus the Southern Fish. In that direction, you will be looking away from the flat plane of our Milky Way, where most of our galaxy’s stars reside, and toward intergalactic space. When you look at the Loneliest Star Fomalhaut you are looking some 90 degrees from the plane of our galaxy’s equator. When you look toward Fomalhaut, you’re looking away from the Milky Way pancake, and out the south window of the galaxy. When the Moon is no longer there to guide you, try star-hopping from the Great Square of Pegasus to Fomalhaut. The 4 stars making up the Great Square of Pegasus might be visible, despite the moonlight. The Great Square of Pegasus appears high in the south to overhead by around 7pm in late November. Draw a line through the Great Square’s two westernmost, or right-hand, stars. Extend that line southward to land on the bright star Fomalhaut. Once you find Fomalhaut, you’re looking out the galaxy’s south window. The exact location of the south galactic pole lies east of Fomalhaut, in the faint constellation Sculptor.

Friday marks the 131st. birthday of Edwin Powell Hubble. Hubble’s name is most widely recognized for the “Hubble Space Telescope”, which was named in his honor. The American astronomer is considered the founder of extragalactic astronomy who provided the first evidence of the expansion of the universe. Hubble proved that many objects previously thought to be clouds of dust and gas and classified as “nebulae” were actually galaxies beyond the Milky Way. In 1923 to 1925, he identified Cepheid variables in “spiral nebulae” M31 and M33 and proved conclusively that they are outside the Galaxy. Hubble provided evidence that the recessional velocity of a galaxy increases with its distance from the Earth, a property now known as the “Hubble–Lemaître law” which implies that the universe is expanding. Earlier in 1912, the American astronomer Vesto Slipher was the first to observe the shift of spectral lines of galaxies, providing the first evidence that the light from many of these nebulae was strongly red-shifted, indicative of high recession velocities.

This is the Dudley Observatory Skywatch Line for Wednesday, November 18th, and Thursday, November 19th, written by Louis Suarato.

The 17% illuminated, waxing crescent Moon sets at 7:42 p.m., Wednesday. Before setting, Saturn, Jupiter, and the crescent Moon form a sweeping arc pointing down to the southwestern horizon after sunset. Thursday night, the crescent Moon and two gas giants form an acute triangle. Look for the Moon 5 degrees to the left of Saturn and 8 degrees to the left of Jupiter. Jupiter’s largest moon, Ganymede will emerge from eclipse at 7:11 p.m., and Callisto’s transit will end at 8:39 , Thursday night. Mars remains bright in the constellation Pisces from dusk until dawn. Venus rises at 4:11 a.m. in the constellation Virgo. Virgo’s brightest star, Spica is 5 degrees to the south of Venus. The bright star to the upper left of Venus is Bootës’ brightest star, Arcturus. Mercury rises at 5:24 a.m., 14 degrees below Venus.

Comet C/2020 M3 (ATLAS) has recently reported to be as bright as magnitude 7.5. The Comet is making its way through the constellation Orion. Orion can be seen above the southwestern horizon before dawn. Thursday morning, look for Comet ATLAS 3 degrees to the west of the star Meissa. Meissa, or Heka, is at the right shoulder of the Hunter, above brighter Bellatrix. On November 14, the comet made its closest approach to Earth, speeding at the rate of 32,019 miles per hour, and at the distance of 33, 313,846 miles. The comet moves across the sky at the width of the Full Moon every 6 hours. The comet’s coma is estimated to be 211,00 miles wide. Comet ATLAS will not return to the vicinity of our planet until the tear 2159.

Wednesday evening, while Saturn, Jupiter and the crescent Moon are pointing down at the Southwestern horizon, there will be a short, 2nd magnitude pass of the International Space Station below them. The ISS will emerge from the south-southwestern horizon at 6:15 p.m., and will rise southward toward the star Fomalhaut in the constellation Piscis Austrinus, where it will disappear into Earth’s shadow.

This is Dudley Observatory’s Skywatch Line for Monday and Tuesday November 16th, and 17th, written by Joe Slomka.

The Sun sets at 4:31 PM; night falls at 6:09. Dawn breaks at 5:12 AM and ends with sunrise at 6:50.

Monday’s Moon sets at 5:49 PM. Tuesday’s 3-day-old Moon rises in Sagittarius at 9:41 AM, appears 11% illuminated, 32 arc-seconds in size and sets at 6:42 PM.

Sagittarius still has Jupiter, Saturn and Pluto as residents. Jupiter is still the first to rise at 11:18 AM, glows with minus 2nd magnitude, appears 35 arc-seconds wide and sets at 8:23 PM. Dwarf Planet Pluto rises next at 11:20 AM, glimmers with 14th magnitude, appears as a tiny dot and sets before Jupiter at 8:17 PM. Pluto lies about 1° below Jupiter. Saturn rises next at 11:30 AM, shines with zero magnitude and appears about 16 arc-seconds in extent and sets at 8:42 PM. All three are quite low on the southwestern horizon by 7 PM, about 12° high. Now is the time for sky watchers to catch last looks before they become too low.

Mars rises in Pisces at 2:47 PM, flashes with minus 1st magnitude, sized 17 arc-seconds, highest at 9:05 PM and sets at 3:28 PM. Mars is 43° high at 7 PM. It, too, slightly dims and shrinks daily as Earth pulls away from it. Again, observers should catch it while it is still easily examined.

Aquarius houses Neptune and Dwarf Planet 1Ceres. Neptune rises at 1:49 PM, shining with 7th magnitude, appears 2 arc-seconds in size, 41° high, best observed at 7:27 PM and sets at 1:08 AM. 1Ceres rises at 2:03 PM, glows with 9th magnitude, best observed at 6:40 PM and sets at 11:16 PM. It can be found in Aquarius’ knee above the bright star Formalhaut and also 20° away from Neptune. Both objects require detailed sky charts and telescopes.

Uranus, in Aries, rises at 3:40 PM, shines with 5th magnitude, 3 arc-seconds wide, best seen at 10:31 PM and sets at 5:26 AM.

Venus, in Virgo, blazes with minus 4th magnitude, appears 12 arc seconds, 85% lit and rises at 4:08 AM. Mercury rises last in Libra, glows with minus zero magnitude, 5 arc-seconds big and rises at 5:15 AM. Venus appears next to Virgo’s brightest star, Spica, about 4° away. Mercury rises during Civil Dawn to the lower left of

Venus and Spica. Binoculars will help in locating both.

November has two meteor showers. The Taurids appear most of the month. They seem to originate near the Pleiades star cluster. The equally sparse, but more famous, Leonid meteor shower also happens this month. This year, the Leonids peak at 11 PM Tuesday evening. Some meteors will be visible after nightfall, but most are better observed after Midnight; its highest between 3 and 5 AM in the southeast. The Leonids are famous because they are the debris of Comet Temple-Tuttle, which orbits the Sun about every 33 years; the meteor shower also follows this cycle. Occasionally, the Leonids have generated a meteor storm, producing hundreds or thousands of meteors per hour. The storms of 1833 and 1966 are legendary. This year, the Moon provides no interference – ideal conditions. This is an average year for Leonids, with a maximum of 20 per hour under ideal conditions. Bright meteors will be seen streaking from Leo’s mane, identifying them as a Leonid. The Leonids are also famed for their “trains.” As the meteor streaks toward Earth, it heats and ionizes upper atmosphere gasses, creating tiny clouds that are twisted by high winds. These “trains” can persist for minutes. Binoculars are the best instrument to see these “trains.” Remember, November nights can be chilly and the observer should dress warmly.

This is Dudley Observatory’s Skywatch Line for Friday, November 13, through Sunday, November 15, written by Sam Salem.

On Friday, Sun rises at 6:45am and sets at 4:33pm; Moon rises at 4:28am and sets at 3:55pm. New Moon occurs on Sunday at 12:07am. This new Moon occurs only 17 hours after perigee, the Moon’s closest approach to Earth.

In the eastern pre-dawn sky on Friday, the crescent Moon will sit above Mercury and below much brighter Venus. Look for Virgo’s brightest star Spica, sitting off to the Moon’s right. Then, look for the very bright star Arcturus, in constellation Bootes the herdsman, way off to the upper left. Mercury glows at magnitude –0.7, only slightly dimmer than it appeared just days ago. Mercury now sits just 2 degrees west of magnitude 4 Kappa (κ) Virginis. Nearby is bright Venus about 1.5 degrees southeast of Theta Virginis.

On Sunday, Mars will cease its westward motion through the stars of constellation Pisces, ending a retrograde loop that began in early September. From this point on, Mars will resume regular easterly prograde motion and pass out of Pisces in early January. Mars, at about magnitude –1.8, is a month past opposition and shrinking into the distance. But it’s still 18 arcseconds wide in a telescope. Mars shines bright yellow-orange in the east-southeast at dusk, below the Great Square of Pegasus. It’s at its highest and best in the south around 10pm.

Jupiter and Saturn tilt down in the west-southwest during and after twilight. Saturn is now only about 4 or 5 degrees to Jupiter’s upper left. Watch the two planets creep toward each other for the rest of the fall.

These moonless nights could be a chance to spot Uranus with your naked eyes if you have a clear, dark sky. Uranus, at magnitude 5.7 in constellation Aries the ram, sits high in the east by around 8pm. It sits about 20 degrees lower left of Mars. Uranus is only 3.7 arcseconds wide. But that’s enough to appear as a tiny fuzzy ball, not a point, at high power in a good small telescope. Neptune, at magnitude 7.8 in constellation Aquarius, is equally high in the south at that time you look for Uranus. Neptune is 2.3 arcseconds wide. It’s harder to resolve, except in good seeing conditions.

Spot Altair high in the southwest soon after dark. Brighter Vega shines three or four fists to its right. Two distinctive little constellations lurk above Altair. Delphinus the Dolphin is hardly more than a fist at arm’s length to Altair’s upper left. The second constellation is the smaller, fainter Sagitta the Arrow. It is slightly less far to Altair’s upper right. Use binoculars to help you locate these two little constellations.

Draw a line from Altair to Vega, continue the line onward by half as far. You now point at the Lozenge, the pointy-nosed head of constellation Draco, the Dragon. Draco’s brightest orange star Eltanin is the tip of the Dragon’s nose. It’s always pointing toward Vega.

This is the Dudley Observatory Skywatch Line for Wednesday, November 11th, and Thursday, November 12th, written by Louis Suarato.

The 15% illuminated, waning crescent Moon sets at 3:04 p.m., Wednesday. Look for Mars in Pisces high over the east-southeastern horizon and Saturn and Jupiter in Sagittarius over the south-southwestern horizon at twilight. Venus rises at 3:57 Thursday morning in the constellation Virgo, joining the 11% illuminated, crescent Moon 7 degrees above it. Virgo’s brightest star, Spica, will be 6 degrees directly below Venus. Mercury rises around 5:30 a.m., adding to the beauty of bright -4 magnitude Venus, Spica, and the crescent Moon within a 12.5 degree span.

Thursday morning also brings the peak of the Northern Taurids meteor shower. While the origination of the Taurid and Sothern Taurid meteor showers are believed to be the dust from the Comet 2P/Encke, The source of the Northern Taurids is believe to derive from Asteroid . Comet Encke is a periodic comet that competes one orbit around the Sun once every 3.3 years. This is the shortest orbit of any bright comet. Comet Enke was first recorded by Pierre Mechain on January 17, 1786. Johann Franz Encke was the first to calculate it as a periodic comet in 1819. Encke is known for slow moving meteors, and bright fireballs. Look to the south of the Pleiades star cluster for the radiant of this meteor shower. You can expect to see 10 to 15 meteors per our from late Wednesday night into Thursday morning.

Comet C/2020 M3 (ATLAS) remains the brightest comet in the sky at the magnitude of 7.7. Comet ATLAS is still observable in the constellation Orion, moving east of Rigel toward the star Bellatrix. The constellation Orion should be high enough in the sky after 11:30 p.m. for you to observe Comet ATLAS with binoculars. Comet ATLAS is on a 139 year orbit around the Sun. The comet will reach its closest approach to Earth on November 14 at 0.0358 astronomical units, or 3,327,817 miles.

This is the Dudley Observatory Skywatch Line for Monday and Tuesday November 9th, and 10th, written by Joe Slomka.

The Sun sets at 4:38 PM; night falls at 6:15. Dawn begins at 5:04 AM and ends with the Sun rising at 6:42.

Monday’s Moon sets during the afternoon. Tuesday’s 24-day-old Moon rises a 12:40 AM in Leo, appears 24% illuminated and sets at 2:32 PM. Wednesday’s Moon, in Virgo, rises at 1:54 AM and also sets during daytime.

Sagittarius continues to house Jupiter, Pluto and Saturn. Jupiter rises at 11:42 AM, shines with minus 2nd magnitude and appears 38 arc-seconds in size; it sets at 8:44 PM. The Great Red Spot can be telescopically observed at 8:22 PM, Tuesday. Dwarf Planet Pluto rises next at 11:47 AM, glimmers with 14th magnitude and appears as a small dot; it also sets at 8:44 PM. Saturn rises at 11:56 AM, smolders with zero magnitude, appears 16 arc-seconds wide and sets at 9:07 PM. Opportunities for observing planet events are becoming rare and should be taken whenever conditions permit.

Aquarius accommodates Neptune and Dwarf Planet 1Ceres. Neptune rises at 2:17 PM, glowing with 7th magnitude, appears 2 arc-seconds broad, highest at 7:54 PM and sets at 1:36 AM. 1Ceres rises at 2:13 PM, sparkles with 8th magnitude, is best observed at 7:55 PM and sets at 1:38 AM. Both may require sky charts, available from astronomy magazines and websites. Ceres lies between Saturn and Neptune.

Mars rises in Pisces at 3:17 PM, sparkling with minus 1st magnitude, sized 36 arc-seconds, highest at 9:34 PM and sets at 3:55 AM. Mars, too, daily dims and shrinks as Earth pulls away from it.

Uranus, in Aries, rises at 10:59 PM, shines with 5th magnitude and appears 3 arc-seconds small. Mars is sited between Neptune and Uranus.

Finally, Venus and Mercury share Virgo. Venus rises first at 3:52 AM, blazing with minus 3rd magnitude, a respectable 12 arc-seconds and appearing 84% lit. Mercury follows by rising at 5 AM, glares with minus zero magnitude, 7 arc-seconds in size, and 57% illuminated. Spica, the brightest star in Virgo lies between the two planets. Both planets set during daytime.

By midnight, the constellations Orion and Taurus are quite high. If a meteor streaks across the sky from the northeast, chances are it belongs to the Taurid Meteor showers. These showers last most of November; the Southern Taurids peaked November 5th, while the Northern Taurids peak on the 12th. These meteor showers are rather weak – the debris of periodic Comet Encke. Taurids are rather slow, traveling about 31 kilometers per second, but very bright. Northern Taurid’s radiant lies near the beautiful Pleiades star cluster; brilliant meteors seem to fly in different directions from that point.

This is Dudley Observatory’s Skywatch Line for Friday, November 6, through Sunday, November 8, written by Sam Salem.

On Friday, Sun rises at 6:36am and sets at 4:41pm; Moon sets at 12:07pm and rises at 9:13pm. Moon reaches its last quarter phase at 6:46 pm on Sunday. That day, the Moon will rise at around midnight, and remains visible in the southern sky all morning. At last quarter, the Moon is illuminated on its western side, towards the pre-dawn Sun.

Jupiter and Saturn tilt down in the west-southwest during and after twilight. They tilt more steeply and sink lower as they creep closer together week by week. Observe them with a telescope early before the end of twilight, before they sink lower toward the southwest later in the evening. Both planets are somewhat farther and smaller than they were during summer. Saturn is now only 5 degrees to Jupiter’s upper left. Watch them creep toward each other for the rest of the fall. They’ll pass just 0.1 degrees apart at conjunction on December 21st, low in twilight as fall turns to winter.

Venus, at magnitude –4.0 in constellation Virgo, shines brightly, but not very high, in the east before and during dawn. Venus rises in darkness about an hour before dawn’s first light. Mercury rapidly emerges into dawn view this weekend. By the morning, look for Mercury low in the east-southeast well below Venus, about 45 minutes before sunrise.

Mars, at magnitude –2.0 in constellation Pisces, is three weeks past opposition and noticeably less bright. Mars climbs into high view earlier every night. At dusk, Mars glares fiery orange in the east-southeast. It’s at its highest and best in the south by 10pm.

Use the Big Dipper’s bowl stars to find the bright golden star Capella, in constellation Auriga the Charioteer. The top two bowl stars of the Big Dipper guide you to Capella. Capella is sometimes called the Goat Star. The star name, Capella, is the Latin word for nanny goat. Near Capella, you’ll find a tiny asterism, a noticeable pattern on the sky’s dome, consisting of three fainter stars. This little triangle of stars is called the Kids, or baby goats. This weekend, Capella shines well up in the northeast after dark. Look for the Pleiades, three fists to Capella’s right. As evening grows later, try to find orange Aldebaran, in constellation Taurus, climbing up below the Pleiades. Then by about 10pm, Orion clears the eastern horizon below Aldebaran.

Vega is the brightest star in the west in early evening. Its little constellation Lyra extends to its left. Farther left, about a fist and a half at arm’s length from Vega, is 3rd-magnitude Albireo, the beak of Cygnus. This is one of the finest and most colorful double stars for small telescopes. Farther on, in the same direction, find the 3rd-magnitude Tarazed, in constellation Aquilla the Eagle. Just past Tarazed, look at the 1st-magnitude Altair, in Aquilla.

This is the Dudley Observatory Skywatch Line for Wednesday, November 4th, and Thursday, November 5th, written by Louis Suarato.

The 82% illuminated, waning gibbous Moon rises at 7:24 p.m. Wednesday, at the foot of Castor, the Gemini twin. Look .2 of a degree above the Moon with binoculars to see open star cluster M35. M35, also known as NGC 2168, was discovered in 1745 by Philippe Loys de Cheseaux. This star cluster is almost as wide as a Full Moon and is 3,870 light-years away. When not overwhelmed by the brightness of the close Moon, you can see several hundred stars, of which 120 are brighter then 13th magnitude.

Saturn and Jupiter are about 5 degrees apart over the southern horizon after sunset. The two gas giants will continue to close until they are less than a degree apart on December 21st. Jupiter sets at 9:05 p.m., and Saturn will set 25 minutes later. Wednesday night, all four Galilean moons will stretch out to the planet’s west, from the closest being Ganymede, then Io, and Europa, to Callisto at the far end.

Mars remains in the sky for most of the night, shining at magnitude -2.01. Venus rises in Virgo at 3:41 a.m., followed by Mercury 2 hours later. Look for 3rd magnitude star Gamma Virginis 1.1 degree to the left of Venus Thursday morning. The bright star 4 degrees to the right of Mercury is Spica, Virgo’s brightest.

The brightest visible comet currently is C/2020 M3 (ATLAS). Comet ATLAS, discovered on June 27, 2020, was recently reported to be magnitude 8.5. ATLAS is an anacronym for the Asteroid Terrestrial-impact Last Alert System, which discovered the comet earlier this year. Comet ATLAS has entered the constellation Orion from Lepus, and can be found 3 degrees to the east of Rigel at the foot of the Hunter.