Skywatch Line for Friday, September 2, through Sunday, September 4, 2016

This is Dudley Observatory’s Skywatch Line for Friday, September 2, through Sunday, September 4, written by Sam Salem.

The Sun rises at 6:22am and sets at 7:28pm on Friday. Try to locate the young waxing crescent Moon and Jupiter in the western sky shortly after sunset. Venus, shining above the crescent Moon and Jupiter, should be a little easier to spot than Jupiter this evening. Use binoculars or a wide-field scope to start looking for the thin crescent Moon near Jupiter and Venus in the bright sky just above the west-southwest horizon. Venus outshines Jupiter and stays out a little later after sunset. The waxing crescent Moon sets at 8:12pm, Jupiter sets at 8:11pm, and Venus sets at 8:24pm on Friday evening. The crescent Moon will be much easier to spot on Saturday evening as the, then 5% illuminated, waxing crescent Moon sets at 8:40pm. Try to spot the crescent Moon, Venus, and Jupiter low in the Western sky 30 minutes after sunset. On Sunday evening, the slender crescent Moon shines quite close to star Spica, the brightest in the constellation Virgo, the Maiden.

Jupiter will exit the evening sky to enter the morning sky in late September while Venus will remain bright in the evening sky until March of next year. Day by day, Venus is climbing upward, toward Saturn, while Saturn is descending sunward, toward Venus. Venus will meet up with Saturn in a conjunction on October 30.

This weekend is good for observing Neptune. The most distant known planet is at opposition on Friday. Opposition occurs when the Sun, Earth, and a superior planet, a planet that orbits the Sun outside Earth’s orbit, are approximately in a straight line. Earth and Neptune will be in the same direction as seen from the Sun. At opposition, the planet is visible almost all night, reaching the highest altitude around midnight and setting around sunrise. This weekend, Neptune rises around 7:24pm and sets around 6:29am. At that point in its orbit, where Neptune is roughly closest to Earth, the planet appears bigger, brighter, and nearly completely illuminated as we see a “full planet”, analogous to a full Moon. The far planet is up all night at its brightest at magnitude 7.8. Neptune is bright enough to be viewed in binoculars and small telescopes. Neptune transits the meridian (the imaginary line that joins north and south, and passes directly overhead) a little before 1:15am. The planet is currently making its way through the constellation Aquarius. The planet is positioned just a little more than one degree southwest of lambda (λ) Aquarii. In a telescope, the planet looks like a pale, blue-green point of light.

On September 3,1976, the unmanned spacecraft Viking 2 landed on Mars and took the first pictures of the Marian surface. Viking 1 was the first to arrive on the surface of Mars on July 20, 1976. The two identical spacecraft, Viking 1 & Viking 2, each consisting of a lander and an orbiter, flew together and entered Mars orbit. Viking 2 lander settled down at Utopia Planitia, while the Viking 1 lander touched down on the western slope of Chryse Planitia (the Plains of Gold). The landers examined the Martian soil and analyzed its atmosphere and weather. In addition, the two landers conducted three biology experiments designed to look for possible signs of life. These experiments discovered enigmatic chemical activity in the Martian soil, but provided no clear evidence for the presence of living microorganisms in soil near the landing sites.

Skywatch Line for Wednesday, August 31st and Thursday, September 1st, 2016

This is the Dudley Observatory Skywatch Line for Wednesday, August 31st and Thursday, September 1st written by Louis Suarato.

The 1% illuminated, waning gibbous Moon rises at 5:28 a.m. Wednesday. The New Moon occurs at 5:03 a.m. Thursday. September will have two New Moons, the second occurring on September 30th. The second occurrence of a New Moon in the same month is known as a Black Moon. A Black Moon is also referred to the third of four New Moons in a season. The next Black Moon of this type will occur August 21, 2017. A Black Moon can also refer to a month without a Full Moon. This can only happen in the month of February, and will next occur in February of 2018.

Venus and Jupiter are separating, and are 4 degrees apart. You’ll require a clear western horizon at sunset to see these two planets. In the south-southwest, Mars, Saturn and the star Antares form an isosceles triangle, with Mars and Saturn separated by 6.1 degrees, Saturn and Antares are also 6.1 degrees apart, and the distance between Mars and Antares at 4.9 degrees.

130 years ago Thursday, the first photo of the Ring Nebula was taken by Eugene von Gothard. In 1886, Gothard photographed the central red-dwarf star of the Ring Nebula, also known as M57. M57 is a planetary nebula in the constellation Lyra. A favorite target of amateur astronomers, the Ring nebula was formed when ionized gas was expelled into the interstellar medium by its central star during its last stage of evolution. Look for the Ring Nebula between the stars gamma Lyrae and beta Lyrae and to the left of Lyra’s brightest star, Vega.

Star Parties will be hosted, weather permitting, by the Albany Area Amateur Astronomers, this Friday and Saturday night at the Landis Arboretum in Esperance, NY. Directions to the arboretum can be found at

Skywatch Line for Monday and Tuesday August 29th and 30th, 2016

This is the Skywatch Line for Monday and Tuesday August 29th and 30th.

The Sun sets at 7:39 PM; night falls at 9:15. Dawn breaks at 4:37 AM and ends with sunrise at 6:18.

Two pairs of bright planets illuminate the darkening sky. Venus and Jupiter are very low on the western horizon, and require an unobstructed view. The lucky observer sees Venus blazing at minus 4th magnitude, four degrees above the horizon, appearing 90 percent illuminated and setting at 8:29 PM. Jupiter appears at minus 1.7 magnitude two degrees below Venus. It sets at 8:24 PM.

The second planetary pair occupies the southwestern sky. Saturn glows at zero magnitude and appears about 25 degrees high. Red Planet Mars is actually brighter but smaller in our telescopes and 5 degrees to Saturn’s lower left. Note the red star Antares below Mars. All three set by 11:30 PM.

While evening plants were setting, Neptune was rising in Aquarius. It appears as an eighth magnitude blue-green dot near the brighter star Hydor, also called Lambda Aquarii. It remains up all night, but needs a detailed star chart to locate it amid similar looking stars. Neptune is best viewed at 1:10 AM. The same applies to Uranus in Pisces. It is brighter at 5.7 magnitude and appears slightly larger in our instruments. It, too, needs detailed charts to find it and is best viewed at 3:50 AM.

The waning 28 day-old Moon rises 4:25 AM Tuesday. It shines at minus 2.5 magnitude and appears about 4 percent illuminated, 13 degrees high in the East. Wednesday’s Moon rises at 5:28 AM and is 1 percent illuminated. This poses a challenge to find the skinny crescent in 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 story 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 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 upper left star in the square and continues 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 26, through Sunday, August 28, 2016

This is Dudley Observatory’s Skywatch Line for Friday, August 26, through Sunday, August 28, written by Sam Salem.

The Sun rises at 6:14am, sets at 7:39pm and the Moon rises few minutes after midnight on Friday. The last-quarter Moon is situated in Constellation Taurusthis weekend. The best time to view it is in the dawn sky when it is highest and relatively free from the distorting effects of our atmosphere. Watch the terminator, the division between the illuminated and the dark part of the Moon, slowly sweeping across the lunar surface. The Moon’s familiar features look different during sunset illumination, when in waningphase, as opposed to sunrise when in waxing phase. Things appear altered. To demonstrate this effect, examine one or two features at both first and last quarter Moon. Try to observe the prominent craters ofthe Apennine Mountains region (Ptolemaeus, Alphonsus and Arzachel) under different lighting conditions over many nights. This helps you develop a better sense of each crater’s true shape. Astronomy magazines and online references offer Moon maps you can use to guide you to these lunar features.

On Friday, Venus and Jupiter are only 1 degree apart, very low in the west after sunset. This is less than a finger-width at arm’s length. Jupiter is upper left of Venus, Mercury at lower left, soon after sunset.

On Saturday, start looking low in the west about 20 minutes after sunset for a close pairing of Venus and Jupiter. Jupiter is almost 0.1 degrees left of Venus. This is the closest conjunction the two planets will have this year. You might need binoculars to differentiate between the two objects. Use the binoculars to try to locate the much fainter Mercury a few degrees to Jupiter-Venus lower left. Jupiter is moving to the lower right of Venus, only 1 degree apart on Sunday.

Orion, the Hunter, and Sirius, the Dog, can be seen in the early morning sky. Orion’s three prominent Belt stars point to Sirius. Sirius is part of the constellation Canis Major, the Greater Dog. It follows Orion into the sky close to dawn. Sirius marked the flooding of the Nile in Ancient Egypt when it first becomes visible in the eastern horizon for a brief moment just before sunrise, after a period of time when it had not been visible. Orion and the twinkling star Sirius will become visible in the evening by winter. Orion was low in the west after sunset around March and April. As Earth orbits the sun, all the stars rise two hours earlier with each passing month.

Skywatch Line for Wednesday, August 24th and Thursday, August 25th, 2016

This is the Dudley Observatory Skywatch Line for Wednesday, August 24th and Thursday, August 25th written by Louis Suarato

While looking at celestial objects, have you wondered “How old is that?”. It is estimated that our solar system, and most of its components, such as the Sun and planets, were formed approximately 4.6 billion years ago. This was determined mostly by radioactive dating techniques used to derive the age of meteorites. Our Moon formed a bit later, about 4.47 billion years ago. The age of stars can be estimated by measuring their stellar luminosity and rotational speed. As stars age, their luminosity significantly increases. Knowing the mass of a star, and the rate of luminosity, the age of a star can be determined. Sirius, the brightest star in our sky, is estimated to be 240 million years old. The stars forming the Summer Triangle asterism, Deneb, Vega, and Altair, are 10 million years old, 240 million years old, and 1.2 billion years old, respectively. This method can also be used to estimate the age of star clusters, although there may be a variety of stellar masses, and phases of evolution within the cluster. The stars in the Pleiades are estimated to have formed approximately 100 million years ago. The stars in the Great Globular Cluster of Hercules, also known as M13, are estimated to be 12 to 13 billion years old. Nebulae, which form from the gravitational collapse of interstellar gases, are much younger. The Orion Nebula is estimated to be 3.002 million years old. The age of galaxies is determined by observing the light waves emanating from that galaxy. Light travels in waves, and these waves always travel at the same speed, 186,000 per second. Light waves from distant galaxies appear to be stretched out. Scientists say this light is “red-shifted”, since red light is the most “stretched out”, and longest wave of all the colors we can see. The average age of known galaxies is 9 to 14 billion years. The Andromeda galaxy is estimated to be 9.006 billion years old. The Milky Way Galaxy is estimated to have formed 13.21 billion years ago.

The Last Quarter Moon occurs at 11:41 p.m. Wednesday. Mars is now 2 degrees above Antares, and 4 degrees below Saturn, forming a vertical line. The Jupiter, Mars, Venus trianglecontinues to close. Look over the western horizon to see these three planets after sunset.

Skywatch Line for Monday and Tuesday August 22nd and 23rd, 2016

This is the Skywatch Line for Monday and Tuesday August 22nd and 23rd,

The Sun sets at 7:45 PM; night falls at 9:30. Dawn begins at 4:26 AM and ends with sunrise at 6:11.

The darkening sky contains two sets of three bright objects. The first set is difficult to see, unless you have an unobstructed western horizon. Venus is the brightest of the group, at minus 3.9 magnitude; but, it is only four degrees above the horizon. Next brightest Jupiter glows at minus 1.7 magnitude about five degrees east of Venus. Tiny Mercury twinkles at 0.6 magnitude. All three hover mere degrees above the horizon and set by 8:49.

The second set consists of Saturn, Mars and the star Antares. For months, we have been tracking the celestial triangle these bodies form. Now the triangle is gone. Monday and Tuesday night, they form a line six degrees long and about 25 degrees altitude. Saturn is the topmost, shining at 0.4 magnitude. Its ring system is still stunning to first time viewers. Mars, at minus 0.4 magnitude, lies in the middle, about four-and-half degrees below Saturn. Its red color is unmistakable. While Saturn is a grand view, Mars is too small to see surface details. The red star Antares, 2 degrees below Mars, marks the line’s bottom. Note the colors of Mars and Antares and understand why the star was called “the Rival of Mars.” They are best seen shortly after Sunset before they become too low. All three set by Midnight.

Neptune rises in Aquarius at about 8 PM. It is still located near the star Hydor (Lambda Aquarii), making finding the dim blue-green planet easier; Neptune is best observed at about 1:30 AM. Uranus rises about 9:40 PM in Pisces. It is brighter, at magnitude 5.7 and a bit larger than Neptune in our telescopes; it is best seen before Dawn. Detailed star charts help finding these distant Solar System members.

The twenty-day-old Moon rises in Cetus at 10:25 PM; it appears about 71 percent illuminated. Tuesday finds the Moon in Aries and slightly thinner, rising at 11:04 PM. The Moon remains up the rest of the night.

Midnight sees the rise of two star clusters: the Pleiades and the Hyades. The Pleiades rise first and resemble a mini dipper, while the Hyades, rising an hour later, form the face of Taurus, the Bull. In Greek myth, the Hyades and Pleiades are related, both daughters of Atlas and Aethra; both seven in number. The name Hyades derives either from the story of the sisters mourning the death of their brother Hyas, or from the Greek verb “to rain,” since the Hyades’ rise signals the rainy season. They were placed in the sky as a reward for babysitting the infant god Bacchus. The Hyades is the second closet cluster to Earth, second to the Ursa Major cluster. It is about 400 million years old. This cluster is about 150 light-years away and part of the “Taurus Moving Cluster” of stars that are heading towards the star Betelgeuse. Bright star Aldebaran is not a member of this group, and actually midway between Earth and the Hyades. Aldebaran is a giant star, about forty times the Sun’s size and about 125 times brighter.

Skywatch Line for Friday, August 19, through Sunday, August 21, 2016

This is Dudley Observatory’s Skywatch Line for Friday, August 19, through Sunday, August 21, written by Sam Salem.

The Sun rises at 6:07am and sets at 7:51pm. The 98% illuminated Waning Gibbous Moon rises at 8:40pm on Friday and sets at 8:35am the following day. Full Moon occurred on Thursday. The full Moon rises around sunset and sets around sunrise. The Waning Gibbous Moon rises later each night and sets in the west later each day after sunrise. The Moon rises at 9:15pm on Saturday and sets at 9:46am on Sunday morning.

With the Moon just past full, planet observing is the opportunity this weekend. As darkness falls, Mars is about 23 degrees above the south-southwest horizon. Mars is retreating eastward. It resides on the border between Scorpius and Ophiuchus, crossing from the former to the latter constellation on Sunday. Saturn is about 27 degrees above south-southwest around sunset. Mars is a little lower than Saturn, which means it will be that much more challenging to observe. Also, Mars’ disk has shrunk to 11 arc-second. Mars is moving rapidly eastward (leftward) toward Saturn and Antares. The three form a narrower triangle in the southwest at nightfall. The triangle will turn into an almost straight, vertical line on August 23rd and 24th. Mars, Saturn, and Antares set around midnight.

Mercury, Venus, and Jupiter are very low in bright twilight. About 20 minutes after sunset, look for Jupiter due west, then look for Venus to its lower right. They’re just 8 degrees apart on Friday night. They’re heading toward a very close conjunction, barely 0.1 degree apart, on August 27th. Next, try to spot fainter Mercury. It’s closer below Jupiter. Mercury and Jupiter will be at their closest for the month this weekend. The two planets will appear less than 5 degrees apart for the next few evenings. They will be close enough to see inside a single binocular field. Mercury sets at 8:39 pm, Jupiter sets at 9pm, and Venus sets few minutes before 9pm. Use binoculars or a wide-field telescope to help you out with your planet search in the evening twilight.

Neptune reaches opposition and peak visibility in two weeks. The giant planet rises around 8:30 pm and climbs nearly halfway to the zenith in the southern sky by 2 am. The magnitude 7.8 planet lies in Aquarius, 1degree southwest of 4th-magnitude Lambda (l) Aquarii. Use a telescope to observe Neptune’s blue-gray disk.

Asteroid 2 Pallas reaches opposition and peak visibility on Saturday. The second-biggest object orbiting between Mars and Jupiter of magnitude 9.2 will be bright enough to show up through almost any telescope. Find the asteroid on the border between Pegasus and Equuleus, 4 degrees due west of 2nd-magnitude Enif (Epsilon [e] Pegasi), the star that marks the nose of Pegasus the Winged Horse. Enif is the Arabic word for “nose”.

On August 20, 1977, NASA launched the unmanned spacecraft Voyager 2 to explore the outer planets Jupiter, Saturn, Uranus and Neptune and their moons. A 12-inch copper phonograph record carried on board contained greetings in dozens of languages, samples of music and sounds of nature. On August 21, 1989 Voyager 2 fired its thrusters to bring it closer to Neptune’s largest moon, Triton.

Skywatch Line for Wednesday, August 17th and Thursday, August 18th, 2016

This is the Dudley Observatory Skywatch Line for Wednesday, August 17th and Thursday, August 18th written by Louis Suarato

The 99% illuminated, waxing gibbous Moon rises at 7:25 p.m. Wednesday. The Full Sturgeon Moon occurs at 5:27 a.m. Thursday. As the Moon approaches its full phase overnight, it will continually brighten. This is known as the opposition effect, or opposition surge, when the angle of the Sun to the Moon approaches zero. The Moon could appear as much as 40% brighter during this period.

Jupiter, Mercury, and Venus are forming a tight triangle in the west after sunset. Mercury and Venus are separated by 8 degrees, Jupiter and Mercury by 4 degrees, and Venus and Jupiter by 9 degrees. Look low over the western horizon after sunset to see these three planets. In the south-southwest, Saturn and Mars are also closing. These two planets are now separated by 5 degrees. Scorpius’ brightest star, Antares, is only 3 degrees left of Mars. On August 23rd and 24th, Mars will pass between Saturn and Antares. August 17th marks the anniversary of the discovery of Mars’ largest, and innermost Moon, Phobos, by Asaph Hall in 1877. Hall was using the U.S. Naval Observatory’s 26-inch telescope, the largest refracting telescope at the time. Phobos orbits Mars at 3,700 miles above its surface, closer than any other planetary moon. Phobos is so close that it orbits the planet faster than Mars rotates. Phobos completes its orbit in 7 hours and 39 minutes. From the surface of Mars, Phobos rises in the west and sets in the east twice each martianday.

The Albany Area Amateur Astronomers invite you to join them for their monthly meeting Thursday night. This month’s meeting will be held at the Landis Arboretum in Esperance, NY beginning at 7:30. Thursday’s speaker will be Hannah Drew-Moyer. Hannah’s topic will be “Classifying Stars in two Stellar Nurseries”. There will be a star party following the meeting.

Skywatch Line for Monday and Tuesday August 15th and 16th, 2016

This is the Skywatch Line for Monday and Tuesday August 15th and 16th.

The Sun sets at 7:56 PM; night falls at 9:44. Dawn begins at 4:15 AM and ends with the Sun rising at 6:03.

The twelve-day-old Moon blazes 16 degrees high in the southern sky. Monday, it appears about 93 percent illuminated; Tuesday evening it swells to 97 percent. The Moon rises before sunset and is best observed about 11:30 PM. It sets after 4 AM on Tuesday, and 5 AM on Wednesday. The Moon’s brilliance hinders observation of deep sky objects these nights.

Most planets will withstand the lunar light. Venus, is the brightest planet in tonight’s sky, but lies quite low. Three degrees above the horizon, it blazes at minus 4 magnitude and appears about 94 percent illuminated. However, its low altitude requires an unobstructed western horizon for the observer. Venus sets at 8:48 PM.

Mercury is dimmer, at zero magnitude, but a bit higher; it looks about half lit and lies eight degrees east of Venus. Mercury is at aphelion – furthest from the Sun on Monday, and at greatest elongation from the Sun on Tuesday. Its low altitude also hinders observation. Mercury sets at 8:50 PM.

Jupiter is also low in the West, shines at magnitude minus 1.7. While bright, its low elevation also muddies the view. Jupiter sets at 9:13 PM.

The Mars-Saturn-Antares triangle in the southern sky continues to contract. Mars, in Scorpius, shines at magnitude minus .5 and appears about 86 percent illuminated. The Red Planet slowly treks east for its conjunction with Saturn and Antares next week. Saturn, still in Ophiuchus, also travels east, but slower than Mars and lies about 6 degrees East of Mars and four degrees above the red star Antares. All three, especially Saturn, are ideally positioned for viewing at nightfall. Mars sets before Midnight; Saturn and Antares set after Midnight.

Neptune, in Aquarius, rises about 8:35 PM and best observed at 2 AM. Neptune is located near the third magnitude star Hydor (Lambda Aquarii). Star charts enable the sky watcher to find the blue-green eighth magnitude dot amid similar looking stars. The nearby bright Moon may also pose problems for the observer.

Uranus, in Pisces, requires detailed maps to find this fifth magnitude Solar System member. Uranus is best observed about 4 AM, just before Dawn breaks.

Since the Moon inhabits Capricornus on Tuesday night, let us consider this ancient 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; 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. 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 underwater seas, which includes fresh water springs. In 1846, the astronomer Galle discovered planet Neptune in Capricornus.

Skywatch Line for Friday, August 12, through Sunday, August 14, 2016

This is Dudley Observatory’s Skywatch Line for Friday, August 12, through Sunday, August 14, written by Sam Salem.

On Friday, the Sun rises at 5:59am and sets at 8:01pm. This evening, the waxing gibbous Moon is positioned upper-left of the Saturn-Mars-Antares triangle. Mars is the brighter of the two planets, Saturn shines more brilliantly than nearby Antares, the brightest star in the constellation Scorpius the Scorpion. The waxing gibbous Moon sets at 12:48am on Friday. It sets at 1:29am on Saturday; at 2:15am on Sunday.

The main Skywatch show this weekend is the Perseid meteor shower. The Perseid meteor shower will burst into light as Earth passes through the long trail left by Comet Swift-Tuttle. Earth will pass through the path of Comet Swift-Tuttle from July 17 to Aug. 24. The shower’s peak when Earth passes through the densest, dustiest area, which will be on Friday. According to NASA meteor experts, this year, the rate could top 150, and even approach 200 meteors per hour. The meteor shower is in “outburst” as Jupiter’s gravity causing the particles to concentrate in front of Earth’s path. Comet Swift-Tuttle is the largest object known to repeatedly pass by Earth creating the annual Perseid meteor shower. Its nucleus is about 16 miles wide. The pieces of comet debris heat up as they enter the Earth’s atmosphere and burn up in a bright bust of light streaking path across the sky as they travel at 37 miles per second.

The meteors will seem to originate from the constellation Perseus, which appears on the horizon at about 10 pm. However, the most meteors will be visible after midnight. The best time to look for the Perseids is after moonset, which will be around 12:50 am on Friday morning. The Perseids continue late Friday night, a day after their nominal peak. Now the Moon doesn’t set until about 1:30am Saturday morning.

Saturn will be stationary on Saturday. This means that Saturn will come to an apparent stop in one spot relative to the background stars. It’s in front of the constellation Ophiuchus, momentarily motionless relative to the nearby first-magnitude star Antares. Since March 25, Saturn has been moving in retrograde motion (westward in front of the stars). After that short apparent stop on Saturday, Saturn will reverse course and begin moving prograde (eastward in front of the stars). This apparent movement of Saturn, first to the west and then to the east, is due to Earth’s motion in orbit around the Sun. Earth moves faster than Saturn as it orbits in an inner track around the Sun. Similar to watching a slow car from a fast moving car, slower Saturn appears to hang motionless prior to changing its apparent direction of motion to appear to move backwards as the faster Earth passes it. Saturn moves rather slowly through the constellations of the Zodiac. Saturn will finally leave Ophiuchus to move into the constellation Sagittarius in late February 2017.