Skywatch Line for Monday and Tuesday, September 21st and 22nd

This is the Dudley Observatory Skywatch Line for Monday and Tuesday, September 21st and 22nd written by Joe Slomka.

The Sun sets at 6:55 PM; night falls at 8:30. Dawn breaks at 5:07 AM and ends with the Sun rising at 6:42.

The Moon officially turned First Quarter early Monday morning, but rose in our skies in the afternoon. The eight-day-old Moon is already quite bright, at magnitude minus 10.1 and inhabits Sagittarius both nights. It appears a bit more than half illuminated and sets after midnight.

Saturn is the only other brilliant object in our sky. Saturn still resides in Libra and appears midway between Libra and the head of Scorpius. By nightfall, it is only ten-and-a-half degrees high and sets about 9:30 PM.

Twilight’s end reveals the distant planets Neptune and Uranus. Neptune is nearly eighth magnitude in Aquarius, and Uranus is a brighter 5.7 in Pisces. Both require charts, which are found in astronomy magazines, websites and apps. Neptune is best observed at 11:30 PM, and Uranus at 2:04 AM. Neptune sets at 5 AM, while Uranus remains up past sunrise.

By 10 PM, Perseus is moderately up in the eastern sky. At 11:30 PM on Tuesday, the star Algol (also known as Beta Persei) dims. Algol, the “Demon Star,” varies its light every 2 days, 20 hours and 49 minutes. It fades from second magnitude to third – easily seen by the naked eye. The entire cycle takes about nine hours. John Goodricke theorized that a dimmer star was partially eclipsing a brighter star. In 1889, the new technique of spectroscopy verified this theory. The main star is one hundred times the Sun’s luminosity. The eclipsing star is actually slightly brighter than our Sun. There is a third star that orbits the system once every 1.8 years, but plays little part in the occultation. The system is about 96 light years away and the most easily studied “eclipsing binary.” Astronomy magazines and websites provide timetables of its eclipses. Begin observing about 10 PM.

Astronomical Dawn sees the arrival of three bright planets. Venus rises first, at 3:27 AM. It blazes in the dim constellation Cancer. Under magnification, it appears about a third illuminated. Mars emerges a half hour later and is about eleven degrees to Venus’ lower left. Mars lies about one-and-a-half degrees from Leo’s brightest star, Regulus. Jupiter brings up the rear, rising before 5 AM. All three are great observing targets and all will remain in our skies for the rest of the year. They also experience several close conjunctions later this month.

The Vernal Equinox takes place at 4:21 AM Wednesday. This happens when the Sun dives below the projection of Earth’s equator on to the sky. The Sun also rises exactly East and sets exactly West. The word “equinox” means, “equal night.” Indeed, day lasts 12 hours and night also lasts 12 hours. This event signals the beginning of Fall for the Northern Hemisphere and Spring for those in the Southern Hemisphere.

Skywatch Line for Friday, September 18th through Sunday, September 20th

This is Dudley Observatory’s Skywatch Line for Friday, September 18, through Sunday, September 20, written by Alan French.

The Moon will reach first quarter very early Monday morning, so a waxing crescent will dominate the early evening skies this weekend. The Moon sets at 9:57 pm Friday, 10:38 pm Saturday, and 11:25 pm on Sunday.

Weather permitting; the Albany Area Amateur Astronomers, in association with NYS Parks, will hold a public star party at 7:30 pm on Friday, September 18, at the Deerfield Pavilion in Grafton Lakes State Park. At star parties telescopes are set up to provide guests with views of a variety of celestial objects – galaxies, nebular, star clusters, and double stars. Lovely ringed Saturn will be visible low in the southwest during the early part of the star party.

All ages are welcome and there is no admission charge. For directions visit this web site, call the Park office 279-1155, or use the address 100 Grafton Lakes State Park Way, Grafton, NY, 12082.

The star party will be canceled if the skies are mostly cloudy. If weather permits, it will be rescheduled for 7:30 pm on Saturday, September 19. In case of possible cancellation, or for more information, call one of the coordinators, Ray (658-3138) or Bernard (658-9144).

If you look fairly high in the southern sky around 9:00 pm you should spot the bright yellow-white star, Altair. If you’re looking at the right star, it has two fainter stars to either side, one roughly to the lower left and one at about equal distance away on the other side. Altair is the brightest star in Aquila, the Eagle, and its name means “the flying eagle.”

Like most of the brightest stars, Altair shines brightly because it is one of our nearer neighbors, lying at a distance of just under 17 light years. The light you see tonight, traveling 186,000 miles every second, left the star in 1998, the year many watched “Armageddon” and “Deep Impact.” The 1956 science fiction classic, “Forbidden Planet,” was about a visit to Altair 5, a planet orbiting Altair.

The star to the lower left of Altair, Alshain, lies almost 48 light years away, while the one to the upper right, Tarazed, is 390 light years from us. As you can imagine, Tarazed is inherently much brighter than Alshain, but its light is dimmed by its greater distance.

Don’t forget to check next weekend’s Skywatch Line for details on the total lunar eclipse on Sunday night, September 27.

Skywatch Line for Wednesday, September 16th and Thursday, September 17th

This is the Dudley Observatory Skywatch Line for Wednesday, September 16th and Thursday, September 17th written by Louis Suarato

The 12% illuminated, waxing crescent Moon can be seen low over the west-southwestern horizon after sunset before setting at 8:30 p.m. Wednesday evening. This is a good time to see “Earthshine” on the Moon. Earthshine is sunlight reflecting from the Earth onto the Moon’s shadowed surface creating a faint glow. It was Leonardo Da Vinci who concluded that Earthshine was created by the Earth’s reflected sunlight. Da Vinci was wrong about sunlight reflecting off the Earth’s oceans onto the Moon’s oceans, since Earthshine occurs when sunlight reflects off the Earth’s clouds, and, of course, the Moon doesn’t have oceans. But given Da Vinci’s perceptions occurred during the early 1500’s, years before even Copernicus’ heliocentric theories were published, it was an amazing discovery. Earthshine, also known as “The Da VInci Glow”, is best viewed 1 to 5 days before and after the New Moon.

You can find Saturn in the constellation Libra, to the upper left of the crescent Moon. Look about 15 degrees over the southwestern horizon. It was September 17, 1789 when William Herschel discovered Saturn’s moon Mimas. Mimas is the 7th largest moon of Saturn, and the 20th largest in the solar system. Mimas’ most outstanding feature is a gigantic crater known as Herschel. This crater measures one-third of Mimas’ 242 mile diameter.

The pre-dawn hours welcome the arrival of three planets. Venus is the first to rise at 3:40 a.m. Thursday, followed by Mars at 4:08 and Jupiter at 5:15. Look over the eastern horizon for all three planets. Continue to follow these planets as they draw closer during October.

The Dudley Observatory will host two events this week. The first is a lecture and star party at the Octagonal Barn in Delanson, NY on Friday, September 18th, beginning at 7 pm. The lecture will be given by Dudley Observatory’s archivist Josh Hauck on “A Scientific Sweatshop: The Industrialization of American Science and the Women of Dudley Observatory”. The Dudley Observatory will also be hosting “International Observe the Moon Night” at MiSci in Schenectady, beginning at 7 pm on Saturday, September 19th. More information about these events can be found at

The Albany Area Amateur Astronomers will be hosting a Star Watch on Friday, September 18th at Grafton Lake State Park. If the Friday event is cancelled, it will be held Saturday night.

Skywatch Line for Monday and Tuesday, September 14th and 15th

This is the Dudley Observatory Skywatch Line for Monday and Tuesday, September 14th and 15th written by Joe Slomka.

The Sun sets at 7:07 PM; night falls at 8:44. Dawn breaks at 4:58 AM and ends with the Sun rising at 6:35.

At civil twilight, Mercury, which has hugged the western horizon, is very low on Monday; Tuesday finds it below the horizon. Mercury will reappear in the morning sky next month.

The two-day-old Moon is slightly higher than Mercury in the West. It, too, requires an unobstructed horizon. A lucky observer will see a three percent-illuminated Moon. Tuesday finds a thicker crescent Moon higher in Southwest. The Moon sets at 7:47 PM on Monday, 8:16 on Tuesday.

Saturn is much easier to find. It shines moderately high in the Southwest between Libra and the head of Scorpius. Saturn sets earlier daily. So, an astronomer should find the planet as soon as sky conditions permit. The rings are still beautiful, but details become lost as the planet gets lower in our turbulent atmosphere.  Saturn sets at 10:04 PM.

Nightfall witnesses the appearance of distant planets Uranus and Neptune. Neptune rises before sunset, and is best observed, in Aquarius, at about Midnight. Uranus rises in Pisces during Twilight, and remains up all night. Neptune sets at 5:27 AM. Finder charts can be found in astronomical magazines, websites and apps.

Venus rises in Cancer at 3:42 AM. It will be the brightest object in the sky, at magnitude minus 4.5. High powered binoculars or any sized telescope reveals it about 22 percent illuminated. Venus is at maximum brightness now and daily appears higher in the sky.

Mars, in Leo, rises at 4:06 AM and appears about ten-and-a-half degrees to Venus’ left and dimmer than Venus. Under high powers, Mars appears about 98 percent illuminated.

Jupiter brings up the rear, rising in Leo at 5:18. Jupiter is bright, at minus 1.7 magnitude, and appears large in our binoculars and eyepieces. For the rest of the year, it flies in formation with Mars and Venus, and forms a conjunction with Mars on October 17th and Venus on October 26th.

Some objects are perfect binocular targets. Overhead, the constellation Cygnus seems to fly south for the winter. Below the Swan’s neck is a small constellation – Sagitta. The Latin name means “arrow”, and that is exactly what it looks like. Sagitta is a small constellation, and has a single deep sky object, M71. M71 is a star cluster of uncertain type. It displays characteristics of both globular and galactic clusters. It is about 18,000 light years distant, and 30 light-years wide. The binocular observer should see a fuzzy glow about halfway along and a bit below the arrow’s shaft.

Just above the “Arrow’s” tail feathers is a curious object. The Coathanger is an asterism – an image of stars, but not a constellation. This is a perfect binocular target, since a telescope’s magnification destroys the illusion. The Coathanger also goes by the names: Collinder 399 and Brocchi’s Cluster. However, the Coathanger is not a true cluster. Hipparchos satellite measurements reveal that it is just a random placement of stars that happen to resemble an everyday article.

At 7 PM on September 15th, Dudley Observatory will hold its monthly Night Sky Adventures. This month’s event will preview the lunar eclipse of September 27th.

Skywatch Line for Friday, September 11, through Sunday, September 13,

This is Dudley Observatory’s Skywatch Line for Friday, September 11, through Sunday, September 13, written by Alan French.

The Albany Area Amateur Astronomers will take advantage of the dark moonless skies this weekend to hold public star parties at Landis Arboretum in Esperance. The star parties will be at 8:30 pm on Friday, September 11, and Saturday, September 12. At star parties club members set up telescopes to show guests a variety of celestial sights – galaxies, nebulae, star clusters, and double stars. All ages are welcome and there is no admission charge, although we encourage guests to make a modest donation to our fine hosts, Landis Arboretum.

Landis Arboretum is on Lape Road and there are good signs leading there starting at Route 20 and Charleston Street. Turn up Charleston and follow the signs (when driving into Esperance on Route 20 from the east Charleston is the first right after crossing the Schoharie Creek). You can also find directions on their web site. After reaching the farmhouse on the right and parking lot on the left continue up Lape Road for 100 yards. Turn right into the the Meeting House field driveway. It will usually be marked with a “Star Party” sign.

For newcomers there will be a brief introductory talk at 9:00 pm. Meet in the south side of the gravel parking area next to the Meeting House. The talk will include hints about using and enjoying the telescopes and a brief tour of the brighter constellations.

Star parties are canceled if the skies are mostly cloudy or if it’s raining. If in doubt, please call 374-8460 to insure the event is being held. If no one answers the phone, wait for a message.

For early risers there is a lovely pass of the International Space Station visible Sunday morning. We see satellites because they are still up in sunlight while we are down in the Earth’s shadow. Sometimes we can see the satellite move into or out of the Earth’s shadow while it is high in the sky. Sunday morning ISS pass will move out from the Earth’s shadow and come into view while high in the sky. When high in the sky the ISS outshines all the stars. Some times are given in hours, minutes, and seconds.

The ISS will first appear at 4:56 am when 64 degrees above the western horizon. If you look toward the west, you’ll see a huge square of stars, the Great Square of Pegasus, with one corner closest to the western horizon. From the opposite, highest corner, you’ll see a line of stars stretching upward, forming part of the constellation Andromeda. The ISS will first appear to the upper left of the second star in this line.

The ISS will be highest, appearing essentially overhead, at 4:56:25 am, and will vanish in the northeast at 4:59:41 am. Its path will take it well past the famous “W” of Cassiopeia and past the front of the Big Dipper’s bowl.

Skywatch Line for Wednesday, September 9th and Thursday, September 10th

This is the Dudley Observatory Skywatch Line for Wednesday, September 9th and Thursday, September 10th written by Louis Suarato

Wednesday is the birth date of astronomer William Cranch Bond. Born in Falmouth, Maine in 1789, Bond was seventeen years old when he saw his first solar eclipse. This event inspired Bond to become an astronomer. Bond independently discovered the Great Comet of 1811, and he and his son were the first to observe Saturn’s innermost ring at the time, known as the Crepe Ring, also known as the “C” ring. Bond and his son also discovered Saturn’s moon Hyperion. Bond also was a pioneer of astrophotography when he and John Adams Whipple, took the first daguerreotype of a star. That star was Vega. Bond went on to become Harvard University’s “Astronomical Observer to the University”.

Saturn continues to be the only easily visible planet in the nighttime sky. Look for Saturn approximately 20 degrees over the southwestern sky after sunset. You can find Bond’s photo target, Vega, almost directly overhead in the constellation Lyra. Vega, along with Deneb in Cygnus, and Altair in Aquila, form the asterism known as the Summer Triangle. Vega, also known as Alpha Lyrae, is the third brightest star seen from mid-northern latitudes, after Sirius and Arcturus. Vega is about 2.5 times the diameter of the Sun, and is approximately 25 light- years from Earth. This blue-white star shines at magnitude 0.00.

A conjunction you won’t want to miss occurs before sunrise on Thursday. Look over the eastern horizon after 4:30 a.m. for the 8% illuminated, waning crescent Moon between Venus and Mars. The Moon will be about 6 degrees to the right of Mars and 3 degrees to the left of Venus. You’ll notice the brightest star in the sky, Sirius, low over the southeastern horizon and the constellation Orion above. Friday morning offers a viewing challenge when the 3% illuminated, crescent Moon is below Mars and Venus and to the right of Leo’s brightest star, Regulus. You may require a clear view of the horizon and binoculars to see Jupiter rise around 5:30 a.m.

The Albany Area Amateur Astronomers invite you to join them for Star Parties at the Landis Arboretum in Esperance, NY this Friday and Saturday nights. Directions to the arboretum can be found at

Skywatch Line for Monday and Tuesday, September 7th and 8th

This is the Dudley Observatory Skywatch Line for Monday and Tuesday, September 7th and 8th written by Joe Slomka.

The Sun sets at 7:20 PM; night falls at 8:59. Dawn breaks at 4:49 AM and ends with sunrise at 6:27.

The evening sky contains three difficult planets, and an easy one. Mercury is so low on the western horizon that, despite its zero magnitude, it becomes difficult to see amid the setting Sun’s glow. Mercury sets at 8 PM.

Neptune is another difficult planet, because it can easily be mistaken for a star. Neptune rises shortly before sunset, appearing as a tiny blue ball in Aquarius. Uranus, a sister giant planet to Neptune, rises before nightfall in Pisces. It, too, appears as a tiny blue star-like object, but is brighter than Neptune, and can be seen by the naked eye under ideal conditions. Finder charts for both planets can be found in astronomy magazines, websites and apps. Neptune sets at 5:56 AM; Uranus stays up all night.

Saturn is easy; the darkening sky reveals it moderately high in the Southwest between Libra and the head of Scorpius. It is naked eye visible and appears oval in binoculars; it takes a telescope to show off its magnificent ring system. Saturn sets about 10:30 PM.

The twenty-five day-old Moon rises at 2:02 AM on Tuesday, in Gemini. It rises at 2:59 AM on Wednesday. It blazes at minus seventh magnitude on Wednesday, materializing about six-and-a-half degrees to the right of the Beehive Star Cluster. The Moon’s brilliance may wash out details of the star cluster.

Luminous Venus rises in Cancer at 4:06 AM, and by Dawn should be high enough for observation. This month, Venus shrinks in size but becomes a fatter crescent, from 10 percent to 34 percent illuminated. Higher-powered binoculars should reveal the phases; telescopes certainly will.

Venus points to much dimmer Mars, about nine-and-a-half degrees to Venus’s left. Mars rises shortly after Venus and appears as a rust-colored dot amid the sky glow. Later on this month, Venus and Mars join Jupiter to close in on each other for a close conjunction. Mars also slowly creeps towards Antares, the heart of Scorpius.

The Atlantic and Pacific oceans are currently producing multiple hurricanes. As bad as these storms are, they are small compared to storms on other solar system members. The most famous example is the Great Red Spot on Jupiter. This tempest has been continuously observed for three hundred years, and is probably older. The Great Red Spot is actually a high-pressure hurricane, larger than the Earth. Jupiter experiences ordinary thunderstorms that radio amateurs can pick up on their ham radios. Saturn also periodically displays cyclones; in 2010, amateur astronomers discovered the Great White Spot, a thunderstorm over 100 times larger than earthly ones. Uranus displayed an outburst, with 500 miles-per-hour winds, that lasted five years. Neptune also periodically displays severe weather. Finally, our Sun is constantly flaring and sending out clouds of charged particles. Major corporations and governments retain solar scientists to predict space weather, so that satellites, communications and astronauts are protected.

Skywatch Line for Friday, September 4, through Sunday, September 6

This is Dudley Observatory’s Skywatch Line for Friday, September 4, through Sunday, September 6, written by Alan French.

The Moon reaches last quarter Saturday morning, so moonrise over the weekend is late, leaving the evening skies nice and dark. Moonrise is at 11:41 Friday night, 12:30 am Sunday, and 1:22 am Monday.

If you look high overhead at 9:00 pm you’ll see the bright star, Vega, luminary of Lyra, the lyre. Like the majority of the brighter stars in the night sky, Vega is bright because it is one of our nearer stellar neighbors. It is 25 light away and ranks as the fifth brightest star. The only brighter star in the sky at 9:00 pm now is Arcturus, the reddish star in the western sky, which on outshines Vega slightly,.

Lyra is one of the smaller constellations in the sky and its pattern of stars is easy to recognize. If you are facing south and looking high in the sky at Vega, look for a parallelogram of stars to Vega’s lower left. A fifth star to the upper left of Vega completes the pattern of the Lyre. The star to the upper left is quite famous – it is known as the double-double, and is actually four stars. If you have sharp eyes you might be able to see that there are really two stars there, close together. If you can’t see the two by eye, binoculars will nicely reveal them. A telescope and higher power reveals that each of the two is itself a double star, and they are a pretty sight. (If the air is unsteady, they can be hard to discern. Try another night.)

You have probably heard that there is a total eclipse of the Moon on Sunday, September 27, and we’ll be writing about it on that weekend’s Skywatch Line. You may also have heard it called a “Supermoon Eclipse.”

The Moon’s orbit is not quite circular, so its distance from the Earth varies. When it is closest to Earth it appears slightly larger than when it is farthest away. Sometimes the extremes occur close to full Moon, and in recent years the media has taken to sensationalizing the extremes, calling the slightly larger full Moon a “supermoon” and the smaller a “micromoon.”

Exactly how much difference is there between a supermoon and a micromoon? Fortunately, this is easy to show using photography, and has been done numerous times. You can see one example here. In such photographs the difference is quite obvious, but the photos do not reflect two realities of looking at the Moon in the night sky, so they can be misleading.

First, the Moon’s apparent size in the night sky is much smaller than it looks in the photo. To get some idea of how small the Moon actually looks, hold an aspirin at arm’s length. It would completely cover the Moon. When objects are so small it is harder to discern small differences in size. More importantly, we can never do direct comparisons – supermoons and micromoons can only be seen well separated in time.

Here’s an easy experiment you can do if you’re really curious. Draw two circles on a white sheet of paper. Make the first one inch in diameter and the other one and one-eighth inches in diameter. These represent the micromoon and the supermoon. Now place them 115 inches away from your eyes, a distance where they accurately represent the apparent sizes of the micro and supermoons. You should be able to tell which is larger, but it is not as obvious as it was with the larger photos. Now imagine that you look at one circle and then the other, separated in time by many months. (The next micro-full Moon is on April 22, 2016.) The “extremes” of the Moon’s size at full are perhaps not as newsworthy as they seem.

Skywatch Line for Wednesday, September 2nd and Thursday, September 3rd

This is the Dudley Observatory Skywatch Line for Wednesday, September 2nd and Thursday, September 3rd written by Louis Suarato

Wednesday evening, after sunset, Saturn emerges approximately 20 degrees over the southwestern horizon. Saturn sets 14 minutes before 11 p.m. Wednesday night. The time between sunset and the time Saturn sets decreases from 3 1/2 hours to 2 1/2 hours during September. You will require binoculars or a telescope to view Neptune and Uranus. Neptune can be found at the center of the constellation Aquarius above the southeastern horizon at around 10:30 p.m., and Uranus will be in Pisces above the eastern horizon. Just one day past opposition, Neptune shines at 6th magnitude, while Uranus is at 8th magnitude. A finder chart for the precise location of these two outermost planets can be found at You will have about two hours of dark skies after sunset before the 75% illuminated, waning gibbous Moon rises in the east.

The early morning sky offers views of our two neighboring planets, Mars and Venus. Look low over the eastern horizon around 5 a.m. for both. Venus, shining at magnitude -4.02, is the easiest to spot. Venus’ rise will increase from 2 hours before sunset to about 3 1/2 hours before sunset by month’s end. Look about 8 degrees to the left of Venus for the red planet, Mars. Look 3 degrees above Venus for the open star cluster M67 in the constellation Cancer. M67, also known as NGC 2682, was discovered by Johann Gottfried Koehler in 1779. The estimated ages of the stars within this cluster range from 3.2 to 5 billion years, making this one of the oldest known open clusters. There are approximately 500 stars within M67 with over 100 stars similar to our Sun. Look about 8 degrees above Mars and M67 for M44, the Beehive Cluster.

Septembers local astronomy events include Night Sky Adventures @MiSci on September 15th at 7 pm. The program “Total Lunar Eclipse” will provide insight on what will occur during September 28th’s eclipse. On Friday, September 18th at 7 pm, the Dudley Observatory will hold an Octagonal Barn Lecture and Star Party in Delanson, NY. The topic of the lecture will be “A Scientific Sweatshop: The Industrialization of American Science and the Woman of Dudley Observatory. On September 17th at 7 pm, MiSci will be host to International Observe the Moon Night, an international event to encourage observation, appreciation and understanding of the Moon and planetary science.

Also in September, the Albany Area Amateur Astronomers will be hosting star parties at the Landis Arboretum in Esperance, NY on Friday, September 11th and 12th and on Friday, September 18th at Grafton Lake State Park.

Skywatch Line for Monday and Tuesday, August 31st and September 1st

This is the Dudley Observatory Skywatch Line for Monday and Tuesday, August 31st and September first written by Joe Slomka.

The Sun sets at 7:32 PM; night falls at 9:13. Dawn breaks at 4:39 AM and ends with sunrise at 6:19.

Two bright planets blaze in the darkening sky. Mercury lies low above the western horizon. At civil dusk, it is only three degrees high. An observer with an unobstructed view could see a bright ball; but he has to act quickly, Mercury sets at 8:21 PM.

Saturn, on the other hand, is easy to spot; it appears midway between Libra and the head of Scorpius – about twenty-three degrees high. Saturn dips lower daily; and, Earth’s atmosphere increasingly makes detecting details difficult. Its rings are still a wonder to behold, since they are still tilted to maximum. Saturn sets before 11 PM.

Neptune rises with sunset; it is at opposition tonight in Aquarius. We will discuss Neptune in another minute.

The seventeen-day-old Moon rises in Pisces at 8:43 PM on Monday evening and appears about seven degrees to the right of Uranus. A slimmer Moon rises about 10 PM on Tuesday night and appears seven degrees to Uranus’ left. Uranus rises about 9 PM both nights also in Pisces. The bright Moon’s proximity may hinder attempts to locate this giant planet. Finder aids to Neptune and Uranus can be found in astronomy magazines, websites and apps.

Dawn sees Mars and Venus rise in Cancer. Mars rises first at 4:15 AM. To early risers, it looks like a tiny red ball in their telescopes. Recently, planetary scientists announced that Mars once had salty water, just like Earth; but they could not say how acid was Martian water.

Venus follows Mars at 4:38 AM. At minus fourth magnitude, Venus is an easy guide to Mars, about eight degrees above. Venus sports a very thin crescent, about nine percent. Both planets should be observed as soon as possible to avoid the rising Sun’s glare.

As mentioned, Neptune is in “opposition,” which means it rises at sunset and sets at sunrise, and is ideally positioned for observation. Neptune can be seen in binoculars, but it takes a moderately large telescope and a detailed chart to identify it as a planet. Neptune is a gas giant planet. It is also a modern planet. Planet Uranus was discovered in 1781 (it is currently located in Pisces). Irregularities in Uranus’ orbit inspired a search for another planet. Newton’s laws of planetary motion suggested a place to search. Johann Galle and Heinrich D’Arrest discovered Neptune in the place suggested, Aquarius, in 1846. The discovery of Neptune was a triumph of Newton’s theory. Neptune takes over 163 years to orbit the Sun. Neptune is appropriately named. He is the Roman god of the Sea, and now reigns over the vest heavenly ocean. Neptune shines at magnitude 7.8 and appears a tiny 2.3 arc seconds in size. Neptune has two moons, Triton and Nereid. Triton is visible in medium size telescopes; it is the only large solar system moon that orbits its planet backwards, providing an interesting observation target.