Skywatch Line for Monday and Tuesday, August 20th and 21st, 2018

This is the Skywatch Line for Monday and Tuesday, August 20th and 21st.

The Sun sets at 7:49 PM; night falls at 9:35. Dawn breaks at 4:22 AM and ends with sunrise at 6:08.

The evening planetary parade continues. Venus, in Virgo, blazes with minus 4th magnitude low in the western sky. Our binoculars or telescope reveals it to be about 47% lit, but 25 arc-seconds in size. It sets at 9:22 PM.

Jupiter is moderately low in the southwestern sky, blazes at minus 2nd magnitude and is a large 35 arc-seconds in size. It continues to accompany Libra’s bright star Zubenelgenubi. By twilight’s end, it hovers about 13º above the horizon and sets at 10:55 PM.

Saturn is also moderately low in southern Sagittarius. It glows with zero magnitude and appears about 17 arc-seconds in size. Monday night it appears about 4º to the Moon’s lower left; Tuesday night finds it only 2º away from the Ringed Planet. Saturn and its rings are best observed at 9:10 PM; it sets at 1:42 AM.

Mars brings up the rear, in Capricornus. Moderately low at Civil Dusk, it is best observed at 11:07 PM, when it is highest. Mars outshines Jupiter, but appears smaller with only 22 arc-seconds in size. The dust storm continues, but is showing some signs of moderating. It sets at 3:21 AM.

As mentioned, the Moon inhabits Sagittarius both nights. It blazes with minus 10th magnitude and appears 75% illuminated on Monday night; Tuesday finds it brighter and 83% lit. Its glare will degrade views of Saturn and its rings for those nights. The Moon is highest at 8:51 PM on Monday, and at 9:40 Tuesday. It sets at 1:40 AM on Tuesday and at 2:26 AM on Wednesday.

Neptune rises, in Aquarius, near the star Phi Aquarii, during twilight. It shines with 7th magnitude and appears a tiny 2.4 arc-seconds in size. It is best situated at 2:35 AM. Uranus, in Aries, rose at 10:08 PM and shines with 5th magnitude and appears slightly larger. It is ideally viewed at 4:58 AM. Both of these distant members of our Solar System require detailed finder charts from astronomical media.

Mercury makes a Dawn appearance. Rising in Cancer at 4:49 AM, it shines with 1st magnitude, appears about 22% lit, and is about 8 arc-seconds in size. However, at 8º altitude, early observers may need the assistance of binoculars in finding the elusive planet amid the brightening sky.

Ancient peoples saw the sky as the realm of the gods and told stories about their constellations. By midnight, all the constellations that make up the Andromeda saga are visible. We previously mentioned Cassiopeia and Cepheus. Cassiopeia angered some gods and Ethiopia was subjected to severe calamities. An oracle told Cepheus that disasters would end if he chained Andromeda to a seaside rock to be eaten by the sea monster Cetus. Perseus was returning from a mission to kill the Medusa, a woman so hideous that her visage turned people to stone. One version of the myth has Perseus returning by his pet horse Pegasus. He hears Andromeda’s cry for help. The parents, nearby, promise her hand in marriage if he saves her. He kills Cetus and frees Andromeda. “W” shaped Cassiopeia and Cepheus, shaped like a stick drawing of a house, are visible overhead. Pegasus, the flying horse, is a Great Square high in the eastern sky, flying upside down; his neck begins at the lower right star of the square. Andromeda’s chains flow from the square’s upper left star and continue eastward. The famous Andromeda Galaxy lies above the upper chain and is visible to naked eyes in rural skies. Perseus appears to the east of Pegasus, resembling a stick drawing of a man with one long and one short leg. The brightest star in the short leg is Algol, the “Demon Star.” It represents the evil eye of the Medusa. Cetus lies beneath Pegasus and Pisces. It is a dim constellation low on the horizon for our latitude.

Skywatch Line for Friday, August 17 through Sunday, August 19, 2018

This is Dudley Observatory’s Skywatch Line for Friday, August 17 through Sunday, August 19, written by Sam Salem.

On Friday, the Sun rises at 6:04am and sets at 7:55pm; the waxing gibbous Moon rises at 1:04pm and sets at 11:46pm. The first quarter Moon occurs on Saturday at 3:48am, however, the Moon will have set just around midnight that night. On Saturday evening, the stars marking the head of constellation Scorpius line up nearly vertically below the Moon. On Saturday and Sunday, use the Moon to find the star Antares, the brightest star in Scorpius the Scorpion, and the planet Saturn. Saturn, at magnitude +0.2, glows yellow in the south above the spout of the Sagittarius Teapot at nightfall.

On Friday, Venus, at magnitude –4.4, is at greatest elongation from the Sun. However, the planet sits nearly 10 degrees lower at dusk than it did at the end of May because of the shallow angle the ecliptic makes with the horizon as viewed from our area at this time of year. In either the Northern or Southern Hemisphere, the ecliptic makes a shallow angle with the evening horizon in late summer and early fall. On the other hand, the ecliptic intersects the horizon at a particularly steep angle in late winter and early spring in either hemisphere. As seen from Earth, Venus resides 47 degrees east of the setting Sun in its present apparition as the “evening star”. In a telescope, Venus is at or very close to dichotomy, appearing exactly half-lit. For the best telescopic seeing catch Venus as early as you can, preferably long before sunset while it is still high. Venus sets about 1 hour and 30 minutes after sunset. Watch for Venus to follow the Sun below the horizon as dusk gives way to nightfall.

Jupiter, at magnitude –2.0, shines in the southwest in twilight in constellation Libra. Jupiter resides between Spica, about 20° to its lower right, and the head of Scorpius nearly as far to its left. On Friday, the 3rd-magnitude double star Alpha Librae sits almost 0.6° below Jupiter. The wide double star fainter component is magnitude 5.1. That’s only a little brighter than Jupiter’s moons. Jupiter remains close to Alpha Librae through the coming week. Catch Jupiter, as early in the evening as possible, when the planet is highest, roughly 20 degrees above the horizon, and the chances for a steady view are greatest. The planet’s subtle pastel-hued cloud belts appear most vivid when set against a blue, twilight sky. You might also be able to detect the Great Red Spot. The most favorable upcoming Red Spot transit occurs at 9:37pm, Sunday evening. Discerning Jupiter’s detail in a telescope is always tricky and requires patience. When the atmosphere is unsteady you’ll be limited to low magnification power. When the seeing conditions are better, try upping the magnification. Jupiter’s disk has shrunk, from its 44.8 arc-second during opposition last May to 36.1 arc-seconds this week. But that’s still 13 arc-seconds bigger than Mars appears at the moment.

Mars is beginning to fade very slightly, from magnitude –2.8 when it was closest to Earth around the turn of the month to –2.6. It rises higher in the southeast earlier in the evening. Though it’s not very high, it’s at a very southerly declination (–26°) in southern Capricornus. Mars shrinks very slightly this week, from 24 to 23 arc-seconds wide. The dust in its atmosphere continues to thin gradually, allowing faint, low-contrast views of dark surface markings.

Use finder charts for to locate Uranus and Neptune in the east and southeast around 1am. Uranus, at magnitude 5.8, resides at the Aries-Pisces constellations border. Neptune, at magnitude 7.8, sits in constellation Aquarius.

Skywatch Line for Wednesday, August 15th , and Thursday, August 16th, 2018

This is the Dudley Observatory Skywatch Line for Wednesday, August 15th , and Thursday, August 16th, written by Louis Suarato.

The 21% illuminated, waxing gibbous Moon rises at 10:47 a.m., and sets at 10:40 Wednesday night. Look over the west-southwestern horizon after sunset to see the crescent Moon 17 degrees above, and to the left of Venus. Venus is now 50% illuminated. You’ll find Jupiter 22 degrees to the south of the Moon. Thursday, Jupiter will be 7 degrees to the left of the waxing crescent Moon. Also on Thursday, look at Jupiter through a telescope before 10:14 p.m. to see Europa’s and Io’s shadow crossing the planet together. Look on both sides on the southern horizon as Saturn and Mars flank Sagittarius. Mars’ brightness has slightly decreased, but still shines at a brilliant -2.6 magnitude.

When the Moon sets, star hop over the beautiful globular cluster M3. Begin your adventure by following the handle of the Big Dipper asterism within the constellation Ursa Major to Arcturus, the brightest star in Bootes. Then scan 13 degrees, or a fist and a half at arm’s length, to the northwest, where you’ll locate M3. Discovered on May 3, 1764, by Charles Messier, M3 is one of the largest and brightest globular clusters comprised of approximately 500,000 stars. M3 is 33,900 light-years away and is estimated to be 8 billion years old.

August 16th is the birth date of French astronomer Pierre Mechain. Born in 1744, Mechain discovered 11 comets and provided 26 additions to Messier’s catalog, including M104, the Sombrero Galaxy, and NGC 5195, the companion to M51, the Whirlpool Galaxy.

Thursday, beginning at 7:30 p.m., the Albany Area Amateur Astronomers will hold their monthly meeting at the Landis Arboretum in Esperance, NY. No formal presentations are planned, but there will be an ice cream social, and club members are invited to bring items to sell or trade. When darkness falls, there will be a star party.

Skywatch Line for Monday and Tuesday, August 13th and 14th, 2018

This is the Skywatch Line for Monday and Tuesday, August 13th and 14th.

The Sun sets at 8 PM; night falls at 9:49. Dawn begins at 4:11 AM and ends with the Sun rising at 6 AM.

The evening planetary parade continues. Venus, in Virgo, is the brightest planet, but low on the western horizon. It blazes with minus 4th magnitude and appears about half illuminated. As it approaches Earth, it appears larger, but thinner. Watch Venus in binoculars or small scope and see its crescent diminish. Venus sets at 9:38 PM.

Jupiter is next and shines with minus 2nd magnitude. In Libra, it hugs the star Zubenelgenubi, 24º in the south. Tuesday, telescopic observers can the moon Ganymede leave the planet’s face at 9:38 PM. Jupiter sets at 11:20 PM.

Saturn, in Sagittarius, is moderately low in the southern sky, about 22º high and shining with 2nd magnitude. Saturn is best enjoyed at 9:38 PM and sets at 2:10 AM.

Mars, in Capricornus, brings up the rear, glowing with minus 2nd magnitude and slightly outshining Jupiter. Recent views of the Red Planet were marred by the ongoing dust storm. Mars is best observed at 11:39 PM and sets at 3:52 AM.

Monday’s Moon, in Virgo, blazes with minus 5th magnitude, appears about 33 arc-minutes in size and is about 10% lit. Tuesday finds the Moon about 6º above Venus, glaring with minus 7th magnitude, and about 17% illuminated. Monday’s Moon sets at 9:41 PM; Tuesday’s Moon sets at 10:12.

Neptune rises in Aquarius at 8:56 PM, appears as a tiny 2.4 arc-seconds. By nightfall, it is about 9º above the eastern horizon. It is best observed at 2:33 AM, when it is about 30º above the horizon. Uranus, in Aries, rises at 10:35 PM shines with 5th magnitude and is a small 3.6 arc-seconds in size. Both planets require detailed sky charts from astronomical media.

Midnight finds the constellation Perseus rising from the northeast. Perseus hosts the annual Perseid meteor shower, which peaks on August 12th night. Meteors are bits of comets or asteroids that encounter Earth and burn up in our atmosphere. The Perseids originate from Comet Swift-Tuttle, discovered independently by two American astronomers. As a comet approaches the Sun, ices and gases evaporate and take tiny flakes with them. When Earth runs into Swift-Tuttle’s debris path, meteor shower is the result. Saturday was New Moon; today the Moon sets shortly after nightfall. Weather permitting, tonight is an ideal time to observe the Perseid shower. Simply take a lawn chair into a field and enjoy. A blanket helps to ward off the evening chill. You will see bright meteors streaking across the sky, under ideal conditions at 50 per hour. If you backtrack their path, they seem to originate from the constellation Perseus. This is an effect of Earth’s entering the meteor stream; you see a similar result when driving through a snowstorm. If weather does not permit observing on Monday night, a diminished shower will still be visible Tuesday night.

Skywatch Line for Friday, August 10 through Sunday, August 12, 2018

This is Dudley Observatory’s Skywatch Line for Friday, August 10 through Sunday, August 12, written by Sam Salem.

On Friday, the Sun rises at 5:57am and sets at 8:05pm; the waning crescent Moon rises at 4:46am and sets at 7:45pm. The new Moon occurs on Saturday at 5:58am.

Watch Venus, at magnitude –4.4, 45 minutes after sunset. Venus, sits about 10 degrees above the west-southwest horizon. Jupiter shines at magnitude –2.1 and is positioned well past the meridian at dusk. Saturn, at magnitude 0.2, culminates at around 10:15pm. Mars, at magnitude –2.7, is brighter than Jupiter.
Mars is highest in the south around midnight. It’s at a southerly declination (–26°) in southern Capricornus. Mars is still 24 arcseconds wide. The dust in its atmosphere continues to thin gradually, allowing faint, low-contrast views of some dark surface markings.

The annual Perseid meteor shower comes to its peak late Sunday night. You may have noticed a few early Perseids as early as a week or two ago. Conditions are ideal this year as there’s no moonlight. The best time to catch Perseids is after local midnight, when the shower’s radiant is approaching the zenith. You’ll see the most meteors when the shower’s radiant is high from about midnight to dawn. On peak night you may see one or two meteors a minute on average during this time if your sky is very dark. You can see fewer Perseid meteors in the evening hours. The meteors tend to be few and far between at mid-evening. Though this is the best time of night to try to catch an earthgrazer. These are elongated, long-lasting meteors that travels horizontally across the sky. Earthgrazers are rare but most memorable if you’re lucky enough to spot one.

The summer triangle frames the Milky Way between stars Vega and Altair. Deneb, the brightest star in constellation Cygnus, appears in the middle of the Milky Way’s dim band. Look along the band of the Milky Way this weekend, you’ll notice numerous dark rifts and patches. One conspicuous area, known as the Northern Coal Sack, hides in the southeast of 1.2-magnitude Deneb, This feature is part of a much larger dark conglomeration known as the Great Rift, which bisects the summer Milky Way for much of its length. You don’t need a telescope to spot it as just dark skies. Another well-known dark nebula is Barnard’s E, located a few degrees northwest of 0.9-magnitude Altair, the brightest star in constellation Aquila. Use binoculars or a small, wide-field telescope and look for a ragged, E-shaped blackish blob about one degree due west of 2.7-magnitude gamma (γ) Aquilae. Observing the ghostly E takes some effort. But once you train your eye to look for an absence of starlight, you’ll be able to see other dark nebulas you can pick up with binoculars.

Sunday marks the 141st anniversary of the discovery of the first moon of Mars. On August 12 1877, American astronomer Asaph Hall discovered Deimos. Five days later, on August 17 1877, he observed a second moon, which he named Phobos. In Greek mythology, Deimos and Phobos are the sons of Ares (Mars) and Aphrodite (Venus). Deimos is Greek for “panic” and phobos is Greek for “fear.” These two moons are composed of carbon-rich rock-like C-type asteroids and ice. Their densities are so low that they cannot be pure rock. Both are heavily cratered. Probably, they are asteroids perturbed by Jupiter into orbits that allowed them to be captured by Mars.

Skywatch Line for Wednesday, August 8th, and Thursday, August 9th, 2018

This is the Dudley Observatory Skywatch Line for Wednesday, August 8th, and Thursday, August 9th, written by Louis Suarato.

The 6% illuminated, waning crescent Moon rises at 3:44 a.m. Thursday in the constellation Gemini, to the lower right of its brightest stars, Castor and Pollux. Venus, Jupiter, Saturn and Mars continue to be the highlights of the evening sky. All four can be seen above their respective horizons before 9:47 p.m. when Venus sets. Mercury reaches inferior conjunction Thursday, and will be lost in the glow between the Sun and Earth. Mercury will return to the morning sky toward the end of the month..

Keep an eye out for some early Perseid meteors this week. The Perseid Meteor shower peaks Sunday night, but you may see a few meteors emanating out of Perseus, below Cassiopeia, above the northeastern horizon. While concentrating on that section of the sky, there are two bright binocular targets to see below Cassiopeia. Below the northernmost end of Cassiopeia are two groups of stars known as the Double Cluster. The Double Cluster, also known as Caldwell 14, are two open clusters, NGC 869, and NGC 884. The two clusters are comprised of more than 300 blue-white super-giant stars in each cluster, and are approximately 7,500 light-years away. To the lower right of Cassiopeia, look for our neighboring galaxy, Andromeda. The Andromeda Galaxy, known as Messier 31, is 2.5 million light-years from Earth. Astronomers using the Spitzer Space Telescope, estimate the Andromeda Galaxy contains a trillion stars, more than twice the amount of stars in the Milky Way. Use Cassiopeia to find 3.4 magnitude Andromeda by following the deeper V of the W shape of the constellation down about 15 degrees. The first written account of the Andromeda Galaxy was by Persian astronomer Abd al-Rahman al-Sufi, who documented it as a “nebulous smear” in his Book of Fixed Stars.

Skywatch Line for Monday and Tuesday, August 6th and 7th, 2018

This is the Skywatch Line for Monday and Tuesday, August 6th and 7th.

The Sun sets at 8:09 PM; night falls at 10:03. Dawn breaks at 4:00 AM and ends with the Sun rising at 5:53.

The parade of bright evening planets continues; it spans 120º across the sky. Venus, in Leo, blazes with minus 4th magnitude 13º low on the western horizon. This month, Venus brightens and grows larger in our instruments, but thins its crescent from 57% to 40%; it also closes in on Spica. Venus sets at 9:54 PM.

Jupiter, in Libra, radiates with minus 2nd magnitude and appears about 25º altitude in the South. It also fades and shrinks this month. While binoculars permit views of the giant planet and its moons; telescopes permit more detailed sights. On Tuesday, telescopic observers can see the Great Red Spot (a giant storm) at 9:00 PM. Later that night, they can also see the moon IO begin its trek across the planet at 10:29 PM, at 10:32 the moon Europa reappears from behind Jupiter, at 10:38 the moon Ganymede’s shadow departs Jupiter and, finally, Europa disappears into Jupiter’s shadow. Jupiter sets at 11:46 PM.

Saturn, moderately low in Sagittarius, glows with zero magnitude; it fades and shrinks slightly this month. Still, views of the planet and its glorious rings never fail. It is best observed at 10:07 PM and sets at 2:39 AM.

Mars, in Capricornus, is at its brightest and biggest since 2003. It currently outshines Jupiter, because it just came closest to Earth last week; but during August it fades and shrinks a little. Its low altitude and ongoing planet-wide dust storm means uncertain viewing conditions. Mars’ South Polar Cap, a mixture of water and dry ice, is shrinking due to onset of Martian Spring. The Red Planet is best observed at 12:13 AM and sets at 4:27.

Neptune, in Aquarius, rises at 9:24 PM and lies about 1½º from the star Phi Aquarii. The blue-green planet shines with 7th magnitude and appears a tiny 2.3 arc-seconds. It is best studied at 3:02 AM. Uranus, in Aries, shines with 5th magnitude and is larger with 3.6 arc-seconds in size. Uranus rises at 11:03 PM. Both Neptune and Uranus require detailed sky charts.

The 25-day-old Moon, in Taurus, blazes with minus 7th magnitude and exhibits 22% crescent. It rises at 1:42 AM on Tuesday. Wednesday, finds it in Orion, dimmer with 6th magnitude and a 13% crescent. It rises at 2:35 AM near Orion’s Club.

Since Mars is prominent in Capricornus, let us consider this strange constellation. By nightfall, Capricornus, Aquarius, Pisces and Cetus dominate the southern sky. All are water-based. Capricornus is a unique constellation: The Sea-Goat. The creature has the head of a goat, but the body of a fish. This part of the Zodiac is truly ancient; the Sumerians identified it as early as 1600 BC. A royal seal, from the town of Ur, is on display in the Boston Museum. The seal bears the image of Capricornus, just as it is pictured today. Boundary markers of Mesopotamian kings also depict Capricornus as we do. The source of this animal is a mystery. A people far removed from any large body of water invented it. The Goat-Fish was associated with the god Ea, the master of creation and the god of the underground seas, including fresh water springs. Ea resembles the Roman god Neptune. In 1846, the astronomer Galle discovered the planet Neptune in Capricornus.

Skywatch Line for Friday, August 3 through Sunday, August 5, 2018

This is Dudley Observatory’s Skywatch Line for Friday, August 3 through Sunday, August 5, written by Sam Salem.

On Friday, the Sun rises at 5:49am and sets at 8:14pm; Moon sets at 12:20pm and rises at 11:51pm. Last quarter Moon occurs on Saturday at 2:18pm. Once the last quarter Moon is well up, spot the Pleiades to its left and Aldebaran, the brightest star in constellation Taurus, below the Pleiades.

Venus, at magnitude –4.3, loses a little altitude each week. Jupiter, at magnitude –2.1, sets around midnight. Saturn, at magnitude 0.2, reaches transit altitude at roughly 10:15pm. Mars is at its peak brightness and size for the current apparition. This week, the red planet is closer to Earth than it has been in 15 years. Mars glows at magnitude –2.8, twice as bright as Jupiter. The Martian disc spans 24.3 arc seconds. Mars culminates around 12:30am, which is when it’s best placed for telescopic inspection. Recent reports suggest the Martian dust storm may be starting to settle, providing a reason to be optimistic about telescopic observing of Marian details.

The Lagoon Nebula, M8, and its associated star cluster, lies less than 3° to the lower right of Saturn this week. The Lagoon is the brightest emission nebula of the summer skies. In a dark sky it’s obvious to the naked eye as a small Milky Way patch above the spout of the Sagittarius Teapot. The constellation of Sagittarius features the bright heart of the Milky Way and is rich with star clusters and nebulas. The Small Sagittarius Star Cloud, M24, is one of the most eye-catching objects there. Although it’s made up of an uncountable number of stars, M24 isn’t a cluster so much as an isolated patch of the Milky Way, M24 wouldn’t be considered an individual object at all if it wasn’t surrounded by dark nebulas. M24 is a striking sight in binoculars more than by a telescope. High magnification diminishes the Star Cloud’s visual impact. However, scanning M24 with a scope is the best way to explore the network of dark nebulas that frame the faux cluster.

There are plenty of prominent double stars to enjoy this weekend. Albireo is one of the season’s prettiest. The double star is easy to find. Situated in the constellation Cygnus, Albireo marks the foot of the Northern Cross. The Northern Cross is a prominent asterism that consists of the brightest stars in constellation Cygnus, the Swan. The head of the cross is Deneb, the brightest star in Cygnus. The foot star is Albireo. Albireo’s component stars are both reasonably bright, shining at magnitudes 3.4 and 4.7. You’ll have no trouble spotting them in any telescope, even in strong moonlight. The Albireo pair is a wonderful telescopic sight because of their contrasting colors. The bright primary star is a golden yellow, while its companion is a pale, icy blue. Yellow-orange stars tend to be relatively cool compared with bluish-white ones.

Skywatch Line for Wednesday, August 1st, and Thursday, August 2nd, 2018

This is the Dudley Observatory Skywatch Line for Wednesday, August 1st, and Thursday, August 2nd, written by Louis Suarato.

The Moon sets at 10:17 a.m., and rises at 10:58 p.m., Wednesday, as a 75% illuminated, waning gibbous Moon. At 9:20 p.m., Mars, above the southeastern horizon, and Venus, above the western horizon, are at the same altitude of 7.5 degrees. Although Mars is at its brightest, outshining Jupiter, Venus is still brighter by about 2 magnitudes. Jupiter shines at magnitude -2.10 between the two, about 25 degrees above the southwestern horizon. Saturn can be found about 20 degrees over the south-southeastern horizon, in the stream of stars of the Milky Way representing the steam in the Teapot asterism in Sagittarius. Saturn’s ring-tilt is almost at its maximum of 26.5 degrees.

Aim your telescope a few degrees above Saturn to begin a tour of a string of deep sky objects within the Milky Way above Sagittarius. The first object you’ll find is the Sagittarius Star Cluster, or M24. When you view the stars within M24, you are looking at the stars comprising the Sagittarius-Carina arms of the Milky Way Galaxy. M24 is flanked by open star cluster M23, and M25. The stars within M23 are estimated to be approximately 220 million years old, making this one of the oldest known star clusters in the galaxy. M25 can be found 3.5 degrees to the west of the Sagittarius Star Cloud, M24. At magnitude 4.6, M25 can be seen with the naked eye, but binoculars, or small telescopes will provide more detail of the thousands of young, blue stars within this open cluster.

August 1st is the 200th anniversary of the birth of American astronomer Maria Mitchell. Born in Nantucket, Massachusetts in 1818, Mitchell learned about astronomy from her father at an early age, assisting him determine the exact moment of an annular eclipse. At age 14, Mitchell was calculating navigational routes for local whalers. On October 1, 1847, Mitchell discovered Comet c/1847 T1, also known as Miss Mitchell’s Comet. In 1865, Mitchell and her father moved to Poughkeepsie, NY where she became one of the first professors of Vassar College. At Vassar, she worked with the observatory’s 12 inch telescope, the third largest in the United States at the time. Maria Mitchell also co-founded the Association for the Advancement of Women in the late 1800’s with the goal to improve women’s rights.

Skywatch Line for Monday and Tuesday, July 30th and 31st, 2018

This is the Skywatch Line for Monday and Tuesday, July 30th and 31st.

The Sun sets at 8:18 PM; night falls at 10:16. Dawn breaks at 3:48 AM and ends with the Sun rising at 5:46.

The evening sky presents four bright planets. Venus, in Leo, is the brightest at minus 4th magnitude, appears about half lit, and about 14º above the western horizon. It sets at 10:08 PM.

Jupiter, still in Libra, glows with minus 2nd magnitude and stands 27º high in the southern sky. While binoculars will reveal several of the planet’s moons; telescopes allow viewers to witness the moon IO exit the planet’s face at 10:44 PM on Tuesday. Jupiter sets shortly after midnight.

Saturn, still in Sagittarius, is also moderately high in the southern sky, but to Jupiter’s left. Saturn glows with zero magnitude and appears a large 18 arc-seconds in size. Its glorious ring system is best observed at 10:36 PM. Saturn sets at 3:08 AM.

Mars brings up the rear of this evening parade. In Capricorn, the Red Planet reached Opposition last Friday, when it was best aligned for observation. However, Tuesday, it is at its closest approach to Earth at 35,785,000 miles, a distance not equaled since 2003 and will not occur again until 2035. Mars slightly outshines Jupiter and appears 24.3 arc-seconds in size. This close approach presents opportunities for observers; however, the planet-wide dust storm may obscure its surface features. Recently, a European Martian satellite made a potential discovery. Among the satellite’s instruments was a powerful ground-penetrating radar. The scientists revealed that the radar displayed what appears to be a large body of deep underground water. If true, it would be the first stable water observed; some Mars rovers discovered fleeting indications of water. Mars rose after sunset, is best seen at 12:48 AM and sets at 5:04 AM.

Neptune, in Aquarius, rises at 9:51, shines with 7th magnitude and appears a tiny 2.5 arc-seconds in size. However, the nearby waning, 90%lit Moon, only 3 degrees away, rises at 10 PM on Monday and 10:28 PM on Tuesday. Blazing at minus 11th magnitude, its glare will certainly pose challenges for the astronomer. The Moon is best observed at 3:34 AM on Tuesday and 4:17 AM on Wednesday.

Uranus, in Aries, rises at 11:30 PM and shines with 5th magnitude and a larger 3.6 arc-seconds in size. Its distance from the Moon may permit viewing this giant planet. Both Neptune and Uranus require detailed sky charts to assist the observer.

The first artificial satellite, Sputnik, was launched in 1957. A series of military and scientific satellites followed. However, long before Sputnik, Arthur C. Clarke, a novelist, screenwriter and physicist, had a dream. In 1947, he published a paper predicting that a satellite placed in a special orbit could act as a relay for radio signals. Clarke predicted that, if you launched a satellite to orbit high above the Earth at the same speed as the Earth’s, the satellite would appear to be stationary in the heavens. In May 1960, NASA first launched Echo, a silvered Mylar balloon, which literally bounced signals across the Atlantic. On July 10, 1962, AT&T launched Telstar, a true relay station. Telstar received and retransmitted signals between the US and Europe. Today, many such satellites crowd our skies and make worldwide television, telephone and Internet communications routine. Telstar also paved the way for commercial services like Dish TV and satellite radio.