Skywatch Line for Wednesday, April 8th, and Thursday, April 9th, 2020

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

The post proxigean 99% illuminated, waning gibbous Moon rises at 8:03 p.m. Wednesday. Venus blazes high above the western horizon at -4.62 magnitude and 42% illuminated, and sets at 11:37 p.m. in the west-northwest. Look for the Pleiades star cluster 5 degrees below Venus. The reddish star to the left of Venus is Aldebaran, the brightest in the constellation Taurus. The first planet to rise overnight will be Jupiter, at 2:53 a.m. Thursday. Jupiter will be followed by Saturn at 3:11 a.m., and Mars at 3:34 a.m.in Capricornus.

New photos have revealed Comet C/2019 Y4 (ATLAS) is brightening and is developing a tail. Comet Atlas is currently reported to be 6.9 magnitude. It is expected to reach -1 magnitude as it reaches perihelion on May 31. Comets have been described as dirty snowballs, and as they approach the Sun on their annual orbit, they heat up, their ice melts, and they begin spewing dust. It’s that dust that creates meteor showers when Earth passes through them each year. There are many comets, but only a few are visible through small telescopes, and fewer through binoculars, and very few with the naked eye. Comet Atlas can be seen with binoculars. As it gets closer to the Sun, Comet Atlas will brighten further, and should be able to be seen with the naked eye. You can find Comet Atlas by hopping from Venus to its upper right to Capella, to its upper right to the comet, which will be about 60 degrees above the northwestern horizon at 9 p.m. in the constellation Camelopardalis. If you are under dark skies, you can find Comet Atlas also by fusing Polaris at the end of the Little Dipper. Follow the curve of the Little Dippers handle west to the comet. If you are under light polluted skies, you can find Polaris by using the two stars at the end of the bucket of the Big Dipper and following an imaginary line to Polaris. You’ll find Comet Atlas about 20 degrees to the upper right of Polaris. The distance from the horizon to the zenith, which is directly overhead, is 90 degrees. If you hold your fist out with your extended arm, like a fist bump to the sky, and look out over your arm to the sky, that is about 10 degrees.

Skywatch Line for Monday, and Tuesday, April 6th and 7th, 2020

This is the Skywatch Line for Monday, and Tuesday, April 6th and 7th, written by Joe Slomka.

The Sun sets at 7:28 PM; night falls at 9:07. Dawn begins at 4:49 AM and ends with the Sun rising at 6:26.

The evening sky presents us with two bright lights on different parts of the sky. Monday’s Moon rises at 5:47 PM. Low in the eastern constellation Virgo, it appears about 98% illuminated, 33 arc-minutes in size and about 3° high; by 10 PM, it is about 40° high. The Moon sets Tuesday at 6:33 AM. Tuesday evening, the Moon is officially “Full,” rising at 7:05 PM, appearing the same size, but 9° high. By 10 PM, it blazes 27° high and sets at 7:03 AM, Wednesday. This Full Moon is the closest perigee (closest to Earth) of the year at 10:35 PM and may cause large tides along the coast.

The second bright evening light is Venus, in southwestern Taurus. This month, Venus is at its highest and brightest, blazing with minus 4th magnitude. Its phases diminish from 47% to 25%, but its apparent size swells from 26 arc-seconds to 39. Also, note that the Clouded Planet lies above the Pleiades star cluster. Binoculars or telescopes reveal that it is the closest pass to the Pleiades in recent memory; in April 2028, Venus will pass through the Pleiades.

The pre-dawn planet parade is unraveling. It started off with Mars leading; last week, Mars was between Jupiter and Saturn. This week, Mars trails the other two. Jupiter rises in Sagittarius at 3:42 AM, shining with minus 2nd magnitude and 37 arc-seconds in size. Saturn is next, in Capricornus, glowing with zero magnitude, appearing half Jupiter’s size and rising at 3:26 AM. This month, Jupiter and Saturn continue to converge. Mars, in Capricornus, rises at 3:42 AM, is equal in brightness to Saturn, almost 7 arc-seconds in size and to Saturn’s lower left. This month Jupiter brightens, and enlarges. Saturn remains zero magnitude, but expands to 17 arc-seconds. Mars also remains at zero magnitude but broadens to 7.6 arc-seconds. The planet parade presents a challenge object – dwarf planet Pluto, 2° below Jupiter. If the early observer has an 8-inch or larger telescope and a chart of Pluto’s position, he may be lucky, if observing before the sky brightens.

As night falls, the unmistakable shape of Leo, the Lion, dominates the evening sky. Leo is one of those constellations that looks like its namesake. If one looks past Denebola, the Lion’s Tail, one sees a faint hazy cloud. Binoculars show it to be a galactic star cluster. This cluster is called Coma Berenices.

Unlike most constellations, Berenice was not mythical figure. She was married to Ptolemy III of Egypt. When her brother-in-law involved the Pharaoh in a war, Berenice, like all wives, worried about her husband in battle. She vowed to Aphrodite that she would donate a lock of her hair if Ptolemy arrived home safely. He did; and she fulfilled her promise. One night the royal couple inquired of the court priest-astrologer what happened to her donation. He replied by pointing to a hazy cloud in the sky and said the gods accepted her sacrifice. Berenice is famous for another reason; she is Cleopatra’s grandmother. The modern Libyan city of Benghazi bears a modified version of her name.

Skywatch Line for Friday, April 3, through Sunday, April 5, 2020

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

On Friday, Sun rises at 6:33am and sets at 7:24pm, the waxing gibbous Moon sets at 4:14am and rises at 1:56pm. In the western sky between midnight and dawn on Friday, the waxing gibbous Moon will be positioned less than three finger widths to the lower right of the large open star cluster Beehive, or Messier 44, in the constellation of Cancer, the Crab. The Moon passes through, or close to this cluster frequently because the Beehive is located only 1 degree north of the ecliptic.

On Saturday evening, look right or lower right of the Moon for Regulus, the leading star of Leo. They’re about 5 degrees. Above the Moon by a similar distance or a bit more is Algieba, the second-brightest star after Regulus in the Sickle of Leo The Sickle, a backward question mark, forms the Lion’s stick-figure’s head, neck, chest, and front foot.

Venus, at magnitude –4.5, in western constellation Taurus, is the big, bright white “Evening Star” blazing high in the west during and after dusk. Above Venus are the Pleiades, drawing closer to Venus by about 1 degree per day. On Friday evening, Venus is right in the Pleiades’ left edge. In a telescope, Venus is a trace less than half lit and 25 arc-seconds in diameter. It will continue to enlarge in size and wane in phase and will become a dramatically thin crescent in late May.

Mars, Jupiter, and Saturn are grouped low in the southeast as dawn begins. Jupiter is by far the brightest and catches your eye first. Saturn is about 6 degrees lower left of Jupiter. Mars is near Saturn, passing 1 degree lower right of it.

After dusk in early April, the night sky’s brightest star, Sirius, or Alpha Canis Majoris, sparkles in the lower part of the southwestern sky. Sirius is a hot, white, A-class star located only 8.6 light-years from Earth. This is part of the reason for its bright appearance. Sirius is always seen in the lower third of the sky, for mid-northern latitude observers, through a thicker blanket of Earth’s refracting atmosphere. This produces the strong twinkling and flashes of color Sirius is known for.

Follow the arc to Arcturus, and drive a spike to Spica. Although a bright Moon lights up the sky these next several nights, Arcturus and Spica should be bright enough to withstand the onslaught of moonlight. Spica serves as a perfect example of a 1st-magnitude star, whereas Arcturus beams brighter yet, shining one magnitude, or 2 1/2 times, brighter than Spica. Arcturus is the brightest star in the constellation Boötes the Herdsman. Spica is the brightest light in Virgo the Maiden. Find the Big Dipper asterism in the northeastern sky in the evening sky this month, around 9pm. Once you see the Big Dipper, notice its two parts, the bowl and the handle. Then, extend the natural curve in the Dipper’s handle until you come to a bright orange star, follow the arc to Arcturus. Once you’ve followed the curve of the Big Dipper’s handle to the star Arcturus, you’re on your way to finding the bright, blue-white star Spica. Just extend that same curve on the sky’s dome.

Skywatch Line for Wednesday, April 1st, and Thursday, April 2nd, 2020

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

The First Quarter Moon occurs at 6:21 Wednesday morning. The 53% illuminated, waxing gibbous Moon rises later that day at 7 minutes before noon. As the sky darkens, you’ll find the Moon is at the heart of the Geminin twin, Pollux. To the Moon’s lower right, above the western horizon, will be Venus, with the Pleiades star cluster above it. Thursday night, Venus and the Pleiades will be closer. Use binoculars to see Venus below the brightest stars of the Pleiades. The stars of this cluster are named for the daughters of Pleione and Atlas from Greek mythology. The star cluster is also known as the Seven Sisters, and its brightest stars are named for Sterope, Merope, Electra, Maia, Targeta, Celaeno, and Alcyone. Charles Messier listed the cluster as the 45th object in his catalogue. These stars formed about 100 million years ago, and are approximately 444 light-years away.

Jupiter, Saturn, and Mars rise within 30 minutes of each other. Jupiter is up first at 3:17 a.m., followed by Saturn at 3:37 a.m., and Mars at 3:46 a.m. Thursday. Jupiter and Mars will be separated by 7 degrees, and Mars and Saturn will be separated by 1 degree. During the month, Mars will continue to separate itself further from the two gas giants.

There will be two extremely bright International Space Station passes over our region Wednesday and Thursday nights. The first, on Wednesday night, is brighter, but briefer. This 3.6 magnitude, 3 minute, pass will originate out of the northwest at 9:12 p.m., and sail through the constellation Andromeda, before crossing through Perseus. The ISS will continue through Camelopardalis then enter into Earth’s shadow before reaching the Big Dipper. The second pass, which will occur Thursday night, is not as bright, but longer. This 3.4 magnitude, 8 minute ISS pass will once again emerge from the northwestern horizon, this time at 8:24 p.m. Thursday. It will pass by the Andromeda Galaxy before crossing Cassiopeia. The ISS will continue past Polaris, at the end of the Little Dipper, before reaching the handle of the Big Dipper. The ISS will continue toward the east-southeastern horizon, disappearing between Coma Berenices and Virgo.

Skywatch Line for Monday, and Tuesday, March 30th and 31st, 2020

This is the Skywatch Line for Monday, and Tuesday, March 30th and 31st, written by Joe Slomka.

The Sun sets at 7:20 PM; night falls at 8:57. Dawn breaks at 5:01 AM and ends with the Sun rising at 6:39.

Monday’s Moon rose in Taurus, between the horns, in the morning and sets at 1:36 AM, Tuesday. Tuesday finds the Moon in Gemini, rising at 10:51 AM and setting at 2:34 AM, Wednesday.

The evening sky still hosts planets in Aries. Clouded planet Venus appears about 38° high, blazing with minus 4th magnitude, 48% lit and about 25 arc-seconds in size; it sets at 11:24 PM. Venus appears beneath the Pleiades star cluster, presenting a beautiful binocular view for the beginning observer. Much dimmer Uranus glimmers with 6th magnitude, 3 arc-seconds and about 16° in altitude; it sets at 9:19 PM.

The pre-dawn southeastern sky still contains the planetary parade, but with an added feature. Jupiter rises first at 3:31 AM, in Sagittarius, shining with minus 2nd magnitude, 38 arc-seconds and 13° high. Second, Saturn, in Capricornus, rises at 3:52 AM, glowing with zero magnitude, appearing half Jupiter’s size and 11° high. Third, Mars, also in Sagittarius, rises at 3:54 AM, glowing with zero magnitude, 6 arc-seconds in size, appearing 88% lit and 10° high. Mercury, in Aquarius, rises last at 5:55 AM, glowing with zero magnitude, appearing about 63% illuminated, but only 10° high. To the early riser, Jupiter leads the parade. Saturn appears on top of Mars, 6° removed from Jupiter. For the early riser with at least an 8-inch telescope, there is a challenge planet. Dwarf planet Pluto shares the sky near Mars. It rises at 3:37 AM in Sagittarius, dimly shines with 14th magnitude, 0.1 arc-seconds, 12° high and about 5 ° east of Mars. Astronomy websites and magazines can provide finder charts. Very clear sky and perfect seeing may reward the intrepid observer.

Nightfall finds Canis Major, the Big Dog, almost due South. A chain of stars reaches up from the horizon to the dog’s hindquarters. This is the constellation Puppis. Puppis represents part of the obsolete large constellation, Argo Navis. Jason and his crew, the Argonauts, manned the legendary vessel. For centuries, the ship was a whole constellation. In 1879, astronomers broke it into parts: Puppis (Poopdeck), Carina (Keel), Pyxis (Compass) and Vela (Sails).

Since the constellation Leo dominates tonight’s sky, let’s consider its brightest star: Regulus. Regulus is a sun-like star, burning hydrogen to make helium, but also different. It is about 350 times brighter but only about three and a half times as massive and larger. While our Sun takes 26 days to spin, Regulus spins every 16 hours. This is dangerously close to spinning itself apart! As a result, Regulus is oblate – flatter at the poles and bulging at the equator.

Skywatch Line for Friday, March 27, through Sunday, March 29, 2020

This is Dudley Observatory’s Skywatch Line for Friday, March 27, through Sunday, March 29, written by Sam Salem.

On Friday, Sun rises at 6:45am and sets at 7:16pm, the waxing crescent Moon rises at 8:31am and sets at 10:32pm. Moon sits 8 degrees left of Venus on Saturday evening. As night deepens, you’ll find them forming a triangle with the open cluster Pleiades over them. The main belt asteroid Vesta will be positioned less than four finger widths above the Moon.

During the evening on Sunday, in the western sky, the waxing Crescent Moon will be positioned above the large open star cluster known as the Hyades that outlines the triangular face of constellation Taurus, the Bull. The Moon will also sit to the upper right of bright, orange-tinted star Aldebaran. That star, which marks the bull’s left-hand or southerly eye, is less than half as far away as the cluster’s stars. The Moon, Aldebaran, and the Hyades will all fit nicely within the field of view of binoculars.

Venus, at magnitude –4.2, in eastern constellation Pisces, sits high in the west during and after twilight. Venus doesn’t set now until a good 2½ hours after complete dark. In a telescope, Venus appears half lit, and 23 arc-seconds in diameter. It will continue to enlarge in size and wane in phase for the next two months, becoming a dramatically thin crescent in May.

Mars, Jupiter, and Saturn are grouped low in the southeast as dawn begins. Jupiter is by far the brightest and catches your eye first . Little Mars is moving away from Jupiter eastward toward Saturn. Mars is 3 degrees from Saturn this Saturday. They pass each other by 1 degree on Tuesday. Saturn sits 7 degrees lower left of Jupiter.

This weekend, follow Sirius unaided before sunset and follow Vega unaided early into daylight. Sirius, also called the Dog Star, is the brightest star in the Northern Hemisphere’s sky. Its blue-white, –1.4-magnitude glow should be easy to spot in the south as the Sun sets. Sirius A, the star we see easily from Earth, is about twice the mass of the Sun and about 1.7 times as wide. Hidden within its glow is a second, smaller star, called the Pup. This companion, named Sirius B, is a white dwarf smaller than Earth, with the mass of the entire Sun packed into its tiny frame. Sirius B orbits its larger primary roughly once every 50 years. The two are currently more than 10″ apart, a distance that larger amateur instruments at high magnification under excellent atmospheric conditions can discern. The tiny white dwarf is 10 magnitudes fainter than Sirius A.

The Earth Hour takes place this Saturday from 8:30pm to 9:30pm. Earth Hour is a worldwide movement organized by the World Wide Fund for Nature (WWF). The event is held annually encouraging individuals, communities, and businesses to turn off non-essential electric lights, for one hour, from 8:30 to 9:30pm on a specific day towards the end of March, as a symbol of commitment to the planet. It was started as a lights-off event in Sydney, Australia, in 2007. Since then, it has grown to engage more than 7,000 cities and towns across 187 countries and territories to raise awareness for energy consumption and effects on the environment. In light of the latest developments, the Earth Hour global organizing team is recommending all individuals to take part in Earth Hour digitally this year. Go to the website to explore all different ways you can take part online or at home this Earth Hour. www.earthhour.org

Skywatch Line for Wednesday, March 25th, and Thursday, March 26th, 2020

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

The 2% illuminated, waxing crescent Moon sets at 8:32 p.m. Wednesday. High above the Moon, you’ll find brilliant Venus, 50% illuminated, and shining at -4.5 magnitude. Thursday night, the crescent Moon will be 20 degrees below Venus. Look 7 degrees above Venus for the Pleiades star cluster. On April 3rd, Venus and the Pleiades will only be separated by ¼ of a degree. If you star hop from Venus to the next brightest star to its upper left, Aldebaran, and the next brightest star to Aldebaran’s upper left, you’ll land on Betelgeuse in the constellation Orion. You’ll notice Betelgeuse is brightening again. Jupiter leads the overnight planet parade, rising at 3:41 a.m. Thursday. Mars follows 16 minutes later, and Saturn rises 6 minutes after Mars. Jupiter and Saturn will be separated by 6 degrees. This is the closest these three planets have been in two decades. Wednesday is the 365th anniversary of Christiaan Huygen’s discovery of Saturn’s largest moon, Titan.

Mercury rises at 5:55 a.m. Thursday. Mercury reaches perihelion, the farthest distance from the Sun during its annual orbit, on Thursday. Mercury orbits the Sun once every 88 days at an average distance of 0.387 astronomical units, or 35.9 million miles. Mercury has the highest eccentricity, its variation from a perfectly circular orbit, than any other planet in the solar system, at 0.205. Mercury’s distance from the Sun varies from 28.5 million miles at perihelion, to 57.9 million miles at aphelion.

Comet P/2019 Y4 (Atlas) was discovered on December 28, 2019, in Hawaii, by the ATLAS (Asteroid Terrestrial-Impact Last Alert System), Survey. Comet Atlas will make its closest approach to Earth on May 23, 2020. It will reach perihelion on May 31, and may be seen with the naked eye afterward. Comet Atlas can be seen now by using the Big Dipper’s star, Dubhe to locate it. Look about 20 degrees to the north of Dubhe for the comet. You can also look about 25 degrees above Polaris. Wednesday night, the coordinates will be AZ: +6°10’ ALT: 64°00’.

Skywatch Line for Monday, and Tuesday, March 23rd and 24th, 2020

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

The Sun sets at 7:12 PM; night falls at 8:49. Dawn begins at 05:15 AM and ends with the Sun rising at 6:51.

The Moon turns “New” at 5:28 AM on Tuesday. While the Moon is technically visible at sunrise and sunset, it is so close to the Sun that observation is difficult.

Two planets occupy the constellation Aries on both nights. Venus continues as the brightest of the pair, blazing with minus 4th magnitude, 23 arc-seconds in size, 36° high in the southwest, about 52% illuminated and sets at 11:14 PM. Monday, Venus is at Greatest Eastern Elongation, which means it is most distant from the Sun, about 406,688 Km (252,704 Miles). Venus has an 8-year cycle in which it visits the same patch of night sky, a fact known since ancient times. Uranus accompanies Venus, but is dimmer with 6th magnitude, about 3 arc-seconds, 20° degrees high and sets at 9:45 PM.

The pre-sunrise sky still features the parade of bright planets, but with a difference. Since last week, Mars and Jupiter switched positions; now Mars is between the two gas giant planets, Jupiter and Saturn. All three reside in Sagittarius. Jupiter rises at 3:55 AM, glowing with minus 2nd magnitude and appearing a large 36 arc-seconds. Mars rises at 4:05 AM, shining with 1st magnitude and growing larger with 6 arc-seconds. Saturn brings up the rear by rising at 4:18 AM, shining with zero magnitude and appearing about half Jupiter’s size. By 6 AM, the early riser can see them moderately high in the southeastern sky, about 15° high. Mars lies about 2° from Jupiter and 4° from Saturn. Mercury, although at greatest elongation from the Sun hugs the eastern horizon and is very difficult to spot.

College students being sent home due to a pandemic is not a new thing. The Great Bubonic Plague was roaring through England. Between 1665 and 1666, one quarter of London’s population died. It took several generations for the population to recover.

In his 20’s, Isaac Newton was a student at Trinity College in Cambridge, England. In an early form of “social distancing,” the college sent students home; for Isaac, that meant returning to Woolsthorpe Manor. He continued his Math studies and developed an early form of Calculus. He also acquired prisms and started study and experiments about light and developed his theories of Optics. One account depicts Isaac creating a hole in his shades to generate a beam of sunlight into the room. Finally, there was the famous Apple Tree. While he never was hit on the head by a falling apple, his theory of Gravity revealed that the force was not limited to Earth and Moon, but also planets and falling apples. He later called this period his annus mirabilis (miracle year). When school resumed, he returned to Trinity in 1667, along with his theories. Within 6 months, he was named a “Fellow.” Two years later he became a professor!

Skywatch Line for Friday, March 20, through Sunday, March 22, 2020

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

On Friday, Sun rises at 6:58am and sets at 7:08pm, the waning crescent Moon rises at 5:37am and sets at 3:31pm. Look very low in the east-southeastern sky before sunrise on Saturday to see the delicate crescent of the old Moon sitting a palm’s width to the lower right of Mercury.

Friday is officially the first full day of spring. At equinox, the Sun rises virtually due east and sets due west. That means, on the day of an equinox, the setting Sun hits the horizon at its steepest possible angle. At a solstice, the Sun is setting farthest north or farthest south of due west. The farther the Sun sets from due west along the horizon, the shallower the angle of the setting Sun.

Look west-southwest for a broad wedge of faint light rising from the horizon. It will be below Venus and centered on the ecliptic. This is the zodiacal light, reflected sunlight from interplanetary particles of matter concentrated in the plane of the solar system. You will need to observe from a location without light pollution. Don’t confuse the zodiacal light with the brighter Milky Way to the northwest.

On Friday, the southeastern pre-dawn sky will feature a close conjunction of Mars, at magnitude 0.9, and the -2.1 magnitude Jupiter. The pair will rise few minutes after 4am. On Friday morning, the two planets will be separated by only 42 arc-minutes. The Moon’s apparent diameter is 30 arc-minutes. The pair lies roughly 5.5 degrees below Rho1 (ρ1) Sagittarii. Throughout the encounter, Mars and Jupiter, with its four moons, will appear together in the field of view of a backyard telescope at high magnification. Look east of the pair, and you’ll see Saturn, at magnitude 0.7, 7 degrees east of Jupiter.

On Friday, once darkness falls, look for the constellations Aries and dimmer Triangulum lurking some 12 degrees to 16 degrees from brilliant Venus. Above Venus by 13 degrees are the Pleiades. Venus sets few minutes after 11pm.

The constellation Coma Berenices, also known as Berenice’s Hair, is an open star cluster, a loose collection of stars held together by gravity. The Coma star cluster requires a dark sky to be seen. One way to find it is to use constellation Leo the Lion. Leo is relatively easy to see. The front part of the Lion looks like a backwards question mark, and the back part is a little triangle, which includes the star Denebola. The word Deneb in a star name means tail. This star marks the tail of Leo. Use the pointer stars in the Big Dipper to locate Leo. Instead of going northward from the pointer stars to Polaris, the North Star, go southward instead to find the constellation Leo. Imagine that Leo is holding his tail out. In the place where you might see a “puff” at the end of the Lion’s tail, you’ll notice a fuzzy patch, not too far away from Denebola. This is the constellation Coma Berenices, or Berenice’s Hair. The constellation Coma Berenices once was considered part of the constellation Leo. Try binoculars if you can’t spot this group of stars with the unaided eye.

Skywatch Line for Wednesday, March 18th, and Thursday, March 19th, 2020

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

The 28% illuminated, waning crescent Moon sets at 1:32 p.m. Wednesday, and rises at 4:59 a.m., Thursday. At 8:30 p.m., Venus will be 30 degrees above the western horizon. Venus reaches perihelion on Thursday, its closest distance to the Sun during its annual orbit. Eccentricity measures the degree to which a planet deviates from a circular orbit. An eccentricity of “0” is a circular orbit, and an eccentricity of “1” is a highly elliptical orbit. Venus has the least elliptical orbit of any planet. Venus eccentricity is .007, giving it the least difference in distance between aphelion and perihelion of 910,836 miles. The planet with the highest eccentricity is Mercury with a degree of 0.2056. The difference between Mercury’s aphelion and perihelion is 14,873,929 miles. Venus is the slowest rotating planet in the solar system, spinning at only 4 miles per hour. By comparison, Earth rotates about 1,000 miles per hour. Venus is also he only planet to rotate clockwise.

Utilize the dark skies to observe the Andromeda Galaxy approximately 40 degrees to the northwest of Venus. Thursday morning provides an opportunity to see at least three planets and the crescent Moon. Jupiter is the first to rise at 4:07 a.m., followed by Mars 2 minutes later. The two outer planets will be a degree apart. Saturn rises next at 4:29 a.m., followed by the crescent Moon a half hour later. Use binoculars to attempt to see Mercury above the east-southeastern horizon around 6:40 Thursday morning.

The vernal equinox, or astronomical spring, occurs in the northern hemisphere at 11:50 p.m. Thursday. During the equinox, the Sun crosses the extension of Earth’s celestial equator going from the southern to northern hemisphere. The word equinox translates to equal night, indicating the time of year when, at the equator, the number of daylight hours equal the number of nighttime hours. This is also the time when the terminator on Earth is perpendicular to the equator, equally illuminating both southern and northern hemispheres. The equinox is the only time when the Sun rises in one rotational pole, and sets in another, temporarily putting both poles in daylight. The vernal equinox is also the time when the northern hemisphere begins to tilt toward the Sun, shortening the distance between the Sun’s rays and Earth, and gradually warming the northern hemisphere.