Skywatch Line for Monday and Tuesday, December 10th and 11th, 2018

This is the Skywatch Line for Monday and Tuesday, December 10th and 11th.

The Sun sets at 4:21 PM; night falls at 6:03. Dawn begins at 5:33 AM and ends with the Sun rising at 7:16.

The waxing Moon, in Sagittarius, dominates the evening sky. At 3-days-old, it shines with minus 5th magnitude, appears about 12% illuminated and is 19º high. It sets at 7:24 PM. Tuesday’s Moon is located in Capricornus, brighter, larger, 24º high and sets at 8:23 PM.

Monday’s Moon shares Sagittarius with Saturn. The Ringed Planet is low at 7º and shines with zero magnitude. Now is the time for last looks, since it sets at 5:48 PM.

Mars shares Aquarius with Neptune. The Red planet shines with zero magnitude, appears about 8 arc-seconds in size, appears about 90% lit and is best observed at 5:46 PM, setting at 11:26 PM. Mars also acts as an aid in locating Neptune, about 2º away. Blue-green Neptune is much dimmer at 8th magnitude and much smaller with 2 arc-seconds in size. Neptune is best studied at 5:38 PM and set at 11:13 PM. Finder charts for Neptune are available from various astronomical media.

Uranus is alone in Pisces, located near the star Omicron Piscium. It shines with 5th magnitude and is larger at 3 arc-seconds in size. It hovers about 57º high at 9 PM and is best observed at 8:24 PM, setting at 3:06 AM.

Comet 46P/Wirtanen is rapidly closing in on Earth. It is closest to the Sun on Wednesday and the Earth on Sunday, about 7 million miles. Recent observers report it about 6th magnitude, near the star 94 Ceti, about 6º below the star Menkar (Alpha Ceti). This is the closest approach by a comet since 1950. These facts imply that it should be visible in amateur telescopes, once the Moon has set.

The comet is also quite near a recently discovered supernova, also in Cetus. It was discovered in late November in M77, a Seyfert galaxy, above the northeast galaxy’s corner, about 7.5º from 94 Ceti. It should be visible in larger telescopes. Again, finder charts for both the comet and supernova are available from various astronomical websites.

Dawn skies present two bright planets. Venus, in Virgo, rises about 3:30 AM, blazes with minus 4th magnitude and appears about 34% lit. Mercury, in Libra, is making a return to Dawn skies, rising at 5:28 AM. The elusive planet blazes with minus zero magnitude and appears about half lit. However, it hovers about a degree above the eastern horizon, making an unobstructed horizon necessary.

Winters in the Northeast are notoriously cloudy. However, when skies are clear, the night sky presents a riot of brilliant stars and constellations that seem close enough to reach out and touch. In fact, twenty-three of the fifty brightest stars are visible in tonight’s sky. Orion, the Dogs and Taurus account for the majority of the brightest stars in the heavens. Sirius is not only brightest on this list, but also second only to the Sun in luminosity; it is also the leading light of Canis Major, the Large Dog. About half of the list lies relatively close to us; the other half is intrinsically brighter, though further away. So, if it is clear, bundle up and enjoy Nature’s sky show.

Skywatch Line for Friday, December 7 through Sunday, December 9, 2018

This is Dudley Observatory’s Skywatch Line for Friday, December 7 through Sunday, December 9, written by Sam Salem.

On Friday, the Sun rises at 7:13am and sets at 4:22pm. Every year, toward the end of the first week of December, mid-temperate latitudes in the Northern Hemisphere have their earliest sunsets. For our area, the earliest sunset takes place from December 2nd till December 15th when the Sun sets at 4:22pm. This comes a few days before December solstice. This offset from the solstice date is balanced out by the opposite happening at sunrise as the Sun doesn’t come up its latest until January 2nd.. This offset is caused by the tilt of Earth’s axis and the eccentricity of Earth’s orbit.

On Friday, the new Moon occurs at 2:20am, it rises at 7:16am and sets at 4:58pm, which is very close the sunrise and sunset time. On Saturday, the very young Moon and Saturn pair up very low in the southwest at dusk. Both objects can be seen together in binoculars. Saturn is 1.1 degrees south of the Moon on Sunday. To enjoy this conjunction, you’ll need a location with an unobstructed horizon. Pluto is 0.7 degrees south of the Moon on Sunday night. Use the new Moon to guide you to the dwarf planet Pluto.

Saturn, shining at magnitude 0.5, is nearing the end of its current apparition and sets at the end of twilight, at roughly 6:00pm. Mars, at zero-magnitude, transits the meridian at about the same time Saturn is setting. Mars can still offer patient observers some interesting telescopic views. Mars sets around 11:30pm. Mars is 0.04 degrees north of Neptune on Friday.

Venus dominates the dawn sky. Gleaming at its very brightest, at magnitude –4.9, Venus is impossible to miss as it rises in full darkness around 3:35am. Joining Venus for a brief morning appearance is Mercury at magnitude 0.6. The swift little planet rises approximately one hour ahead of the Sun.

This weekend provides a good opportunity to catch a glimpse of Comet 46P/Wirtanen. The icy visitor is inbound and cruising north through Eridanus toward Taurus. Currently glowing at approximately magnitude 6, the comet won’t be at its brightest until its closest approach with Earth next weekend. However, 46P should be readily visible in binoculars used under a sky free from light pollution. Comet Wirtanen spends the weekend roughly 7 degrees south-southeast of 2.5-magnitude Alpha (α) Ceti, the brightest star in the region. The comet is visible most of the night, but is highest shortly after 10pm.

Friday marks the 113th. birthday of the Dutch-American Astronomer Gerard Kuiper. Kuiper is considered by many to be the father of modern planetary science. He discovered Uranus’s satellite Miranda and Neptune’s satellite Nereid. In addition, he discovered carbon dioxide in the atmosphere of Mars and the existence of a methane-laced atmosphere above Saturn’s satellite Titan in 1944. Kuiper discovered several binary stars which received “Kuiper numbers” to identify them, such as KUI 79. Astronomers refer to a region of minor planets beyond Neptune as the “Kuiper belt”, since Kuiper had suggested that such small planets or comets may have formed there. However he believed that such objects would have been swept clear by planetary gravitational perturbations so that none or few would exist there today.

Skywatch Line for Wednesday, December 5th, and Thursday, December 6th, 2018

This is the Dudley Observatory Skywatch Line for Wednesday, December 5th, and Thursday, December 6th, written by Louis Suarato.

The 2% illuminated, waning crescent Moon sets at 3:47 p.m. Wednesday. Arise early to see the crescent Moon 5 degrees above Mercury. Look low above the south-southeastern horizon after 6:15 a.m. for the Moon and Mercury. The Moon will reach its New phase at 2:21 a.m., Friday. Look higher above the Moon for Venus, now 30% illuminated, and shining at magnitude -4.85. Later this month, Jupiter will be joining the two innermost planets in the pre-dawn sky. Mars and Saturn are the only two easily visible evening planets. Saturn will set at 6:03 p.m., and Mars will set 11:26 Wednesday night.

Take advantage of these moonless nights to observe three binocular to small telescope-viewable comets. Comet 38P/Stephan-Oterma will remain at magnitude 9-10 until January. Wednesday night, after 10 p.m., Comet 98P/Stephan-Oterma will be above the eastern horizon. Look approximately 8 degrees below, and left of the brightest head of Gemini, Pollux, for this comet. The second observable comet is 11.9 magnitude 69P/Taylor. The best time to observe this comet is between 7 p.m., and 2 a.m.. At 10 p.m., Comet 69P/Taylor will be about 40 degrees above the southern horizon, and 30 degrees to the right of Rigel in the constellation Orion. The brightest of the three comets, 46P/Wirtanen, can be found 8 degrees to the right of Comet 69P/Taylor. Comet 46P/Wirtanen will make its closest approach to Earth in over 400 years when it travels to within 7.2 million miles on December 16. That will be among the 10 closest comet approaches since 1950, and in the top 20 approaches since the 9th century. While some predict Comet 46P/Wirtanen to reach 3rd magnitude, others have noted its small size make cutail its brightness and may even its ability to form a tail.

Skywatch Line for Monday and Tuesday, December 3rd and 4th, 2018

This is the Skywatch Line for Monday and Tuesday, December 3rd and 4th.

The Sun sets at 4:22 PM; night falls at 6:03. Dawn begins at 5:28 AM and ends with the Sun rising at 7:09.

Bright planets are becoming difficult to find. Saturn, in Sagittarius, shines with zero magnitude about 10º above the southwestern horizon, low enough to ruin views of its ring system. Saturn sets at 6:12 PM.

Aquarius harbors two planets. Mars shines also with zero magnitude and appears about 89% lit. It lies about 36º high in the southern sky. It is best observed at 5:57 PM and sets at 11:29 PM. The Martian surface is becoming quite littered with spacecraft. The recent INSIGHT lander joins Curiosity, and 5 other NASA spacecraft either orbiting or on the surface. This does not count space efforts by other nations and failed missions. In fact, not long ago, Mars was known for the difficulty for safely placing probes in or around Mars. Neptune is normally difficult to locate; it shines with 8th magnitude and appears a tiny 2 arc-seconds in size. However, on Monday and Tuesday nights, the blue-green planet lies within 2º of the Red Planet, within the same low power field in most telescopes. Neptune is best observed at 6:06 PM and sets at 11:41 PM.

Uranus, in Pisces, is brighter with 5th magnitude and a bit larger than Neptune. It is situated near the star Omicron Piscium. It is best observed at 8:53 PM and sets at 3:35 AM.

Comet 46P/Wirtanen is closing in on Earth. It is found in the constellation Fornax (the Furnace) and heading towards the constellation Eridanus. It will be closest to the sun on Dec 12th and closest to Earth on the 16th. Recent observations place it at 6th magnitude, visible through binoculars and telescopes. Finder charts are available from astronomical media.

The 27-day-old Moon rises at 4:04 AM on Tuesday in Libra. It glows with 5th magnitude and appears about 8% illuminated. Wednesday’s Moon is fainter and thinner about 3% lit and rises at 5:10 AM. Wednesday’s Moon is the last easily observed old Moon. Tuesday’s Moon is about 4º from Venus, which makes seeing a planet during daytime easy. Most binocular fields are about 5º in size; so, both fit the same field of view.

By 9 PM, the constellation Cetus (the Whale) is moderately high in our skies. Occasionally, the Skywatch Line mentions the variable star Algol, which varies its light about every 3 days. However, there is another star in our sky that takes much longer to vary its brightness – Mira. Mira is classified as a pulsating variable. While it was known to ancients, it took the Polish astronomer Hevelius to name it “Mira” – Latin for “Wonderful” in 1662. Most star catalogs call it Omicron Ceti, which is in Cetus. Mira is a binary, two stars orbiting each other. Mira is ancient, about 6 billion years old and about 220 light-years distant. It is the prototype of a class of between 6 to 7 thousand similar variable stars. Mira varies its light every 332 days. Maximum can be between 2nd and 4.9th magnitude; minimum can be between 8.6 and 10th magnitude. The star usually takes 100 days to brighten and twice as long to fade. Most of its light is in the infrared spectrum, but the star is easily seen in ordinary telescopes. In Ultraviolet telescopes, it sports a comet-like tail. The last maximum was December 29, 2017, so its current maximum is just about now and visible in amateur telescopes. Finder charts are available from astronomical media.

Skywatch Line for Friday, November 30 through Sunday, December 2, 2018

This is Dudley Observatory’s Skywatch Line for Friday, November 30 through Sunday, December 2, written by Sam Salem.

On Friday, the Sun rises at 7:06am and sets at 4:24pm; The waning crescent Moon sets at 1:10pm.

On Saturday, Venus is at greatest brightness, shining at magnitude –4.9 in the morning sky. Venus appears brilliant from the time it rises a little before 4am until close to sunrise some three hours later. It stands about 25° above the southeastern horizon an hour before the Sun comes up. The “morning star” reaches an altitude of nearly 30 degrees by sunrise. When viewed through a telescope, Venus spans 40″ and appears one-quarter lit.

Saturn sits less than 10 degrees above the southwest horizon 45 minutes after sunset. It will be impossible to spot in just a few more weeks. Saturn shines at magnitude 0.5, more than a full magnitude brighter than any of the background stars in its host constellation, Sagittarius the Archer. This weekend, the planet’s disk measures 15″ across while the ring system spans 35″ and tilts 26° to our line of sight. Mars, at magnitude –0.1, climbs due south to the meridian at roughly 6:30pm.

Try to spot Uranus, at magnitude 5.7, with your naked-eye this weekend. Uranus sits near the Aries-Pisces border. It is pretty easy to see in binoculars if you know the constellations well enough and with the use of a finder chart.

This weekend moonless evenings are a good opportunity to have the first look at Comet 46P/Wirtanen. Although it won’t be at its brightest until mid-December, the comet should be visible in binoculars or a small telescope as a magnitude 6 fuzz-ball. Comet Wirtanen is currently located in the constellation Cetus and heading northward. The best time to view it is roughly 10pm, when the comet is at its highest and positioned due south. This region of sky lacks bright stars. You’ll have to sweep carefully with your binoculars to catch the comet. Hopefully, in the coming weeks, Comet Wirtanen will brighten to naked-eye visibility as it continues to move northeast into better position.

The Andromeda Galaxy, M31, and the Perseus Double Cluster are two of the most famous deep-sky objects. They’re both cataloged as 4th magnitude. In a fairly good sky you can see each with the unaided eye as faint fuzzies. They’re located only 22° apart, very high toward the east early these evenings. They are located to the right of Cassiopeia and closer below Cassiopeia, respectively.

Vega still shines brightly in the west-northwest after dark. The brightest star above it is Deneb, the head of the big Northern Cross, which is made of the brightest stars of Cygnus. At nightfall the shaft of the cross extends lower left from Deneb. By midnight, it plants itself more or less upright on the northwest horizon.

Saturday marks the 400th anniversary of the first comet observation using a telescope. The Swiss mathematician and astronomer Johann Cysat was one of the first to make use of the then newly developed telescope. Cysat’s most important work was on comets. Cysat concluded that comets circled around the Sun. He demonstrated that the orbit of the comet was parabolic, not circular. Cysat’s observations on the comet are characterized by their great detail. Cysat saw enough detail to be the first to describe cometary nuclei and was able to track the progression of the nucleus from a solid shape to one filled with starry particles.

Skywatch Line for Wednesday, November 28th, and Thursday, November 29th, 2018

This is the Dudley Observatory Skywatch Line for Wednesday, November 28th, and Thursday, November 29th, written by Louis Suarato.

The 72% illuminated, waning gibbous Moon rises Wednesday night at 9:01.. The Moon will reach its Last Quarter phase at 7:19 p.m. on Thursday. Look for Taurus’ brightest star, Regulus, 3 degrees below the Moon on Wednesday. Saturn will be only be a few degrees above the southwestern horizon at astronomical twilight, when the Sun is between 12 and 18 degrees below the horizon. Mars is the most easily visible planet in the night sky. Look about 40 degrees, or four fists at arm’s length, above the southern horizon around 6 p.m. for the red planet.

This week, NASA landed the newest rover on Mars after traveling for six and a half months at an average speed of 6,625 miles per hour. Mars’ atmosphere is only 1 % of Earth’s, providing very little friction to slow down any spacecraft. That is one of the reasons only 40% of any mission to land a spacecraft on Mars by any agency has been successful. The name of the new lander is InSight, and its mission will be the first robotic rover to study the interior of Mars, and determine how rocky planets form.

On November 28, 1964, NASA launched the spacecraft Mariner 4 from Cape Kennedy, Florida. Marina 4 reached Mars on July 14, 1965, and during its flyby, became the first to take close-up photos of the planet.. Mariner 4 flew as close as 6.118 miles to the Martian surface, taking 22 photos, of 1% of the planet. The photos took 4 days to transmit to Earth.

Venus adorns the pre-dawn sky, rising at 3:49 a.m. in Virgo. Spica is to Venus’ upper right, and higher to Venus’ upper left, is Arcturus. The Last Quarter Moon can be seen high above Venus, very close to Regulus. Look over the western horizon for Orion and its brightest stars, Betelgeuse and Rigel, and its clearly distinguishable belt of three stars, Alnitak, Alnilam, and Mintaka. This asterism is also known as the “Three Sisters, or “Three Kings”. Sirius, “the Dog Star”, brightest in Canis Major, and brightest in our sky, can be found by following Orion’s belt to the left.

Skywatch Line for Monday and Tuesday, November 26th and 27th, 2018

This is the Skywatch Line for Monday and Tuesday, November 26th and 27th.

The Sun sets at 4:34 PM; night falls at 6:04. Dawn begins at 5:21 AM and ends with the Sun rising at 7:01.

While four planets grace the evening sky, only two are easily spotted. Saturn, still in Sagittarius, hovers about 13º above the southwestern horizon, shines with zero magnitude and appears a moderate 15 arc-seconds in size. The observer should aim at Saturn before it gets too low and sets at 6:36 PM.

The dim constellation Aquarius contains two planets. Mars shines with zero magnitude, appears about 9 arc-seconds in size and appears about 86% lit. The Red Planet is best observed at 6:08 PM and sets at 11:33 PM. Mars lies about 6º beneath dimmer Neptune. Blue-green Neptune glows with 7th magnitude and appears a tiny 2.3 arc-seconds in size. It is best observed at 6:33 PM and sets at 12:08 AM.

Nightfall reveals Uranus, in Aries, as brighter than Neptune at 5th magnitude, one arc-second larger, and 24º high. It is best acquired at 9:21 PM and sets at 4:03 AM.

Minor Planet 3Juno, in Eridanus, shines with 7th magnitude, is smaller than 1 arc-second and 7º above the eastern horizon. It is best seen at 11:09 PM and sets at 4:55 AM.

Comet 46/P Wirtanen lies in the constellation Fornax, not too far from Juno. In fact, it will move into Eridanus next week. Recent observations reveal it to be about 6th magnitude, visible in binoculars. Neptune, Uranus, 3Juno and Wirtanen all require finder charts, available from astronomical media.

Monday’s Moon rises in Gemini at 8 PM, blazes with minus 11th magnitude and appears about 81% illuminated. Tuesday’s Moon rises 9:08 PM in Cancer, appears a bit smaller and dimmer. The Moon is up for the rest of the night for both days. The Moon’s brilliance may hinder searches for dim deep sky objects, like the nearby Beehive star cluster.

Venus rises at 3:47 AM in Virgo, beams with minus 4th magnitude and appears about 22% lit. It is found near Virgo’s brightest star, Sirius, which shines with only 1st magnitude. Virgo also harbors another comet – 2018V1. It is found near the star Zeta Virginis (Heze) and was observed at 9th magnitude, making it a pre-Dawn reward. Again, finder charts are available from various sources.

The constellation Canis Major rises at about 7:00 PM tonight to Orion’s lower left. The constellation houses the brightest star visible to our skies, Sirius, the “Dog Star”. Although the word “sirius” means, “scorching,” ancients connected the constellation and star with a dog. Sirius is a blue-white double star, larger and hotter than our Sun. It is the closest star visible to northern latitudes, and the fifth closest star to Earth. Since the star is visible in summer, the term “Dog Days” is associated with hot weather. Egyptians worshiped Sirius because its rising meant the Nile’s life-giving waters would soon surge to irrigate the land.

Skywatch Line for Friday, November 23 through Sunday, November 25, 2018

This is Dudley Observatory’s Skywatch Line for Friday, November 23 through Sunday, November 25, written by Sam Salem.

On Friday, the Sun rises at 6:57am and sets at 4:26pm; Full Moon sets at 7:05am and rises at 5:12pm. The full Moon occurs at 12:39am on Friday. As the Moon rises, it is positioned near Aldebaran, the brightest star in the constellation Taurus. Watch the Moon draw farther away from Aldebaran through the hours of the night. On Saturday, the Moon rises around the end of twilight and climbs high through the evening. It’s now below the horns of Taurus, Beta (β) and fainter Zeta (ζ) Tauri. On Sunday and Monday night look for the bright waning gibbous Moon in eastern sky. Notice the two bright stars in its vicinity, noticeable for being both bright and close together on the sky’s dome. These stars are Castor and Pollux in the constellation Gemini.

Saturn shines at magnitude 0.6 and is slowly slipping away into twilight. One hour after sunset, Saturn sits just 10 degrees above the southwest horizon. Mars, at magnitude –0.2, shifts each night a bit more than one Moon diameter along the ecliptic. As a result, Mars remains essentially due south each evening while the background stars appear to slowly advance westward.

At dawn, enjoy observing Venus at magnitude –4.8. Venus rises about 2 hours and forty-five minutes before the Sun. Venus’ overwhelming luminosity presents the greatest viewing challenge. About all you can see of Venus is its phase. Generally, a dark background sky makes the phase more difficult to discern. Locate Venus with your telescope before sunrise then continue to follow it as the sky brightens to deep blue. This allows you to observe the planet while keeping its glare to a minimum. This weekend Venus reaches the meridian, when it’s due south and highest, a little before 10am. At present, Venus is an attractive, 47 arc-second diameter waxing crescent. If you watch over the coming weeks, you’ll see its disk size shrink as the distance between Earth and Venus increases.

Neptune appears stationary on Sunday. Neptune right high in the south, in Aquarius, is harder to locate at magnitude 7.9 in a bright Moon night.

The phrase spring up and fall down gives you some idea of the Big Dipper’s place in the evening sky. On fall evenings the Big Dipper sits way down low in the northern sky. On spring evenings, the Big Dipper shines high above Polaris, the North Star. This weekend use the Big Dipper’s pointer stars, which point to the North Star Polaris, to find the bright golden star Capella in the constellation Auriga, the Charioteer. The top two bowl stars point toward Capella, the Goat Star. Capella is the Latin word for nanny goat. Near Capella, you’ll find a tiny asterism consisting of three fainter stars. This little triangle of stars is called the Kids.

Saturday marks the 379th. anniversary of the first observed transit of Venus. On November 24, 1639, Jeremiah Horrocks, an English astronomer and clergyman, measured a transit of Venus, the first ever to be observed. Applying Kepler’s prediction made in 1631, Horrocks calculated that these transits occurred not

singly but in pairs, eight years apart. Horrocks prepared his simple telescope mounted on a wooden beam to project a solar image onto a piece of paper marked with a six inch graduated circle. From this, he made measurements and calculated that the value for the solar parallax was smaller than previously recorded. He concluded that the Sun was further away from the Earth than previously thought.

Skywatch Line for Wednesday, November 21st, and Thursday, November 22nd, 2018

This is the Dudley Observatory Skywatch Line for Wednesday, November 21st, and Thursday, November 22nd, written by Louis Suarato.

The 98% illuminated, waxing gibbous Moon rises at 3:55 p.m. Wednesday. The Moon reaches its Full phase at 12:39 a.m. Friday. Look for the nearly Full Moon to rise on Thanksgiving evening at 4:26, 5 minutes after sunset. Thursday night, use binoculars to combat the glow of the Moon and find the Pleiades star cluster 15 degrees to its upper left. The star to the Moon’s lower left is Aldebaran, Taurus’ brightest. Aldebaran is an orange giant star located 65 light-years away. Aldebaran translates to “the follower” because it rises, and follows the Pleiades across the sky. Aldebaran, also known as Alpha Tauri, is the 14th brightest star in the sky, ranging from 0.75 and 0.95 magnitude. In 1782, William Herschel discovered Aldebaran’s faint companion. In 1888, S.W. Burnham discovered a 14thmagnitude double star to Herschel’s companion. Aldebaran has exhausted its hydrogen core, and its new helium core has expanded its hydrogen shell to 44 times the diameter of our Sun.

Mars continues to shine brightly in the constellation Aquarius, and can be found about 23 degrees over the southwest horizon at 9 o’clock. This week, NASA will announce the landing site for the Mars 2020 rover, which is scheduled to land on the planet in 2021. Among its other scientific goals, this mission will look for the existence of evidence of ancient life on Mars. Venus rises in Virgo at 4:04 a.m., just 3 degrees to the left of Virgo’s brightest star, Spica.

You’ve most likely noticed how bright the Full or gibbous Moon may look when viewing it through a telescope. You may want to consider obtaining a moon filter for observing under these conditions. A moon filter is similar to sunglasses in that it reduces glare. When placed between the diagonal and the eyepiece, the filter dims the brightness, and displays details more clearly. Moon filters can be fixed or variable. A fixed moon filter allows a fixed percentage of light through the eyepiece. A variable filter allows you to choose the percentage. Moon filters can be threaded between the diagonal and your eyepiece, and are made to fit either 1 ¼ inch or 2 inch diameters.

Skywatch Line for Monday and Tuesday, November 19th and 20th, 2018

This is the Skywatch Line for Monday and Tuesday, November 19th and 20th.

The Sun sets at 4:29 PM; night falls at 6:07. Dawn begins at 5:14 AM and ends with the Sun rising at 6:53.

First magnitude planet Mercury hugs the western horizon at Civil Dusk. It glows with first magnitude, appears about 19% illuminated and a medium size of 9 arc-seconds. However, it lies very low and sets at 5:12 PM. Binoculars and an unobstructed view is required.

Saturn, to Mercury’s upper left, inhabits Sagittarius with a zero-magnitude glow and 15 arc-seconds in size. Now is the time for last looks at the giant planet and its famous rings. Saturn sets at 7 PM.

Mars, in Aquarius, shines with minus zero magnitude, appears about 86% lit and about 10 arc-seconds in size. At Civil Dusk, it is about 32º high. It is best observed at 6:19 PM and sets at 11:37.

About 11º East of Mars, Neptune, also in Aquarius, is dimmer at 8th magnitude, a tiny 2.3 arc-seconds in size and 38º high. It is best observed at 7 PM and sets at 12:36 AM. Uranus, in Aries, is brighter at magnitude 5, is larger at about 4 arc-seconds in size and 32º high. It is best observed at 9:49 PM and sets at 4:32 AM. Minor planet 3Juno was closest to Earth on November 16th and was at Opposition on the 17th. This means that it is ideally situated for observation at about Midnight, shining with 7th magnitude. It is located in the dim constellation Eridanus and is closest to the star 35 Eridani. Comet 46P/Wirtanan is traveling through the constellation Fornax and heading toward Eridanus. The comet is predicted to be at 11th magnitude, but could become brighter. Observers of all these objects should consult finder charts, available in various astronomical media.

Monday’s Moon occupies Cetus. The 11-day-old Moon is about 87% lit and blazes with minus 11th magnitude. It is best observed at 9:14 PM and sets at 3:39 AM. Tuesday’s Moon, in Pisces, is a bit brighter and bigger. It is best studied at 10 PM and sets at 4:45 AM. The brilliant Moon lies close to all the above objects, and may hinder detailed observation.

Comet 2018/V1 (Comet Macholz, Fujikawa, Iwamoto) was simultaneously discovered by amateurs. Located in Virgo, it is closest to the star 90 Virginis. The 10th magnitude comet is visible during the hours before Dawn. Again, finder charts are available from various astronomical media.

Venus shares eastern Virgo with the comet and the bright star Spica. Venus dazzles with minus 4th magnitude and a large 48 arc-seconds in size. The planet climbs the sky this month, but shrinks in size. It rises at 4:07 AM and lies about 2º above Spica.

Comets are leftovers from Solar System formation. They reside in the Kuiper Belt, beyond Pluto, and the further Oort Cloud. Comets are mostly ice, with some dirt mixed in. Most stay in those distant regions. However, a comet may receive a gravitational bump and head into the inner Solar System. There are three basic orbits. Some revisit every few years, for example Halley’s Comet; some come too close to the Sun and evaporate away, like 2013’s Comet Ison. A third type arrives and never returns, like the object Omuamua.