Skywatch Line for Wednesday, May 31, and Thursday, June 1, 2023

This is Dudley Observatory’s Skywatch Line for Wednesday, May 31, and Thursday, June 1, written by Alan French.

The Sun rises at 5:20 A.M. on Wednesday and sets at 8:26 P.M. On Thursday it rises at 5:20 and sets at 8:27. This Thursday has just over 10 minutes more daylight than last Thursday.

The Moon reached first quarter Saturday and is now moving toward full. On Wednesday the Moon will be toward the southeast as the Sun sets, appearing 88% sunlit. The gibbous Moon will be due south and highest, 35 degrees above the horizon, at 10:16 P.M. Thursday night’s Moon will be lower in the southeast as the Sun sets, and will be due south or transit at 11:04 P.M., appearing 95% full and 28 degrees high. The Moon will reach full late this coming Saturday.

While the full Moon tends to draw photographers, the waxing gibbous Moon offers some enticements. Craters and mountains along the terminator show up well and add interest to a photo, and modern “super-zoon” digital cameras, or a telephoto or an interchangeable lens digital camera provide enough image scale to show these details. Today’s digital cameras allow plenty of room for experimenting with exposure settings, and image processing software allows adjustments for best appearance. This writer generally mounts his camera on a tripod, uses a time delay on the shutter, and underexposes by one stop, slightly adjusting lighting in Photoshop Elements. See what gives you the best results!

Venus continues to dominate the western sky after sunset, now shining at magnitude -4.3. Through a telescope, Venus now appears just over half in sunlight. At it catches up with Earth on its faster, inner orbit, it will grow larger, but we’ll see less of its sunlit face. Brightness increases as it moves closer, but decreases because we see a smaller part of the sunlit face. The two almost balance out, but the increase has a slight upper hand. At its brightest, Venus will reach magnitude -4.7 in early July.

At 9:46, the end of nautical twilight, Venus will be 20 degrees above the western horizon, nicely strutting its brilliance. Nautical twilight is the second phase of twilight, when the horizon is still visible at sea. It ends when the Sun is 12 degrees below the horizon and the horizon is no longer visible. (In the morning, it begins when the Sun is 12 degrees below the horizon.)

The third and darkest phase of twilight is astronomical twilight. The Sun is more than 12 degrees below the horizon, but our atmosphere still scatters some of its light into our night sky and brightens it slightly. With a gibbous Moon in the sky, its effect will be invisible. Astronomical twilight ends when the Sun reaches 18 degrees below the horizon and no sunlight reaches our night sky. For us, that is now 10:39 P.M. The time is mostly of interest to serious stargazers on Moonless nights and under dark skies away from light pollution. New York’s Adirondacks include some of the remaining truly dark skies in the country.

The first phase of twilight, civil twilight, is from when the Sun sets to when its geometric center is six degrees below the horizon. During civil twilight only the brightest stars and planets are visible.

Skywatch Line for Monday, Memorial Day, and Tuesday May 29th, and 30th, 2023

This is the Dudley Observatory’s Skywatch Line for Monday, Memorial Day, and Tuesday May 29th, and 30th, written by Joe Slomka.

The Sun sets at 8:25 PM; night falls at 10:34. Dawn begins at 3:12 AM and ends with the Sun rising at 5:21.

The Moon appears in southern Virgo on both nights. Monday’s waxing Moon rises at 2:33 PM, 30 arc-minutes in size, 73% illuminated, 46° high at 9 PM and sets at 2:54 AM on Tuesday. Tuesday’s Moon rises at 3:37 PM, slightly larger, 81% lit, 40° high at 9 PM and sets at 3:14 AM, Wednesday.

Western Venus and Mars continue as a duet, slowing closing in on each other and 11° apart. Venus, in Gemini, blazes with minus 4th magnitude, 22 arc-seconds, 17° high at 9 PM, 58% lit and sets at 11:47 PM. On both nights, Venus and the star Pollux lie 4° apart. Dimmer Mars, in Cancer, fades with 1st magnitude, 4 arc-seconds, 24° high, 60° from the Moon and 93% lit and sets at 12:20 AM. Monday’ s Mars is at aphelion (furthest from the Sun).

The Dawn sky is filling up and all its planets set during daytime. Saturn, in southeastern Aquarius, is the first to rise, at 1:44 AM, glowing with 1st magnitude, appears 17 arc-seconds, 30° high at 5 AM. Neptune follows, 20° to Saturn’s left, in Pisces, it rises at 2:29 AM, 8th magnitude, a tiny 2 arc-seconds and is 27° high at 5 AM.

Jupiter, Mercury and Uranus share Aries. Gas Giant Jupiter, 35° above Neptune, rises at 3:49 AM glimmers with minus 2nd magnitude, 34 arc-seconds and 13° high at 5 AM. Elusive Mercury follows, 11° away, smolders with zero magnitude, 8 arc-seconds, rises at 4:28 AM, is 5° high and appears 40% lit. Even though Mercury is 25° from the Sun (the maximum can be from the Sun) the view is not the best. Astronomy magazines suggest trying next week when Mercury is brighter and higher. Finally, Uranus follows 5° high, 6th magnitude, 3 arc-seconds, 5° high and rises during Civil Twilight at 4:31.

One of the astronomical cliches is that Jupiter’s Great Red Spot has been continuously observed for three centuries. While true, the Spot has been known to change. For example, it is not exactly red now, but closer to rust color. Beginning observers may experience difficulty finding it. When measured in the 1800’s, the storm was 25,000 miles wide. In 1979, Voyager spacecraft imaged it at 15,534 miles. In 1995, British astronomer John Rogers, collaborating with professional and amateur astronomers, measured it at about 12,500 miles and also reported increasing wind speeds. The Great Red spot now has 300 miles-per-hour winds, up from 250. Like an ice skater, it spins faster as it gets smaller. Rogers speculates that, by 2050, it may be known as the Great Red Circle. Hubble Telescope images reveal that it is about 10,253 miles (16,500km) wide. The cause of shrinkage is unknown. Should the Great Red Spot disappear, astronomers are uncertain what would happen. It could reappear, or never return. Remember, this is a weather system, which, like all storms eventually end.

Skywatch Line for Friday, May 26, through Sunday, May 28, 2023

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

On Friday, Sun rises at 5:23am and sets at 8:22pm; Moon sets at 1:32am and rises at 11:23am. The Moon, very nearly first quarter, shines in the Sickle of Leo after dusk on Friday. It’s almost between the Sickle’s two brightest stars, Regulus, lower left of the Moon, and fainter Gamma Leonis or Algieba, to the Moon’s upper right.

First-quarter Moon occurs on Saturday at 11:22 a.m. That evening, the Moon shines under Leo’s midsection, not quite halfway from Regulus lower right of the Moon to Beta Leonis or Denebola, the Lion’s tail-tip, to the Moon’s upper left.

Venus, magnitude –4.3, in the constellation of Gemini, is the brilliant “Evening Star” in the west from twilight into late evening. It still shines nearly as high in the dusk as it ever gets, and it doesn’t set until about 2 hours after dark. Venus is enlarging a little more every day while waning in phase. Next week it’ll appear half lit, then it will become a bigger, dramatically thinning crescent dropping low from mid-June through mid-July.

Mars, magnitude 1.6, in the constellation of Cancer, glows weakly to the upper left of Venus by an ever-shrinking distance of 12° by Sunday. That’s hardly more than a fist at arm’s length. They will not reach conjunction. Mars and Venus will reach a minimum separation of 3.6° on June 30th, then they’ll start to draw apart again as Venus plunges down toward the sunset. This is called a quasi-conjunction, because they don’t pass each other although they do get within 5° of each other.

Jupiter, magnitude –2.1, in the constellation of Aries, is beginning to emerge from the bright glow of sunrise. Look for it very low in the east in about 40 minutes before sunup.

Saturn, magnitude +1.0, in the dim constellation of Aquarius, is moderately low in the southeast before and during early dawn.

Bright star Capella, in the constellation of Auriga the Charioteer, sets low in the northwest soon after dark. That leaves Vega and Arcturus as the brightest stars in the evening sky. Vega, in the constellation of Lyra, shines in the east-northeast. Arcturus, in the constellation of Boötes, is way up very high toward the south. A third of the way from Arcturus to Vega, look for semicircular Corona Borealis, the Northern Crown, with 2nd-magnitude Alphecca as its one moderately bright star. It’s the jewel on the front of the tiara. Two thirds of the way from Arcturus to Vega is the dim Keystone of Hercules, now lying almost level. Use binoculars or a telescope to examine the Keystone’s top edge. A third of the way from its left end to the right is 6th-magnitude M13, one of Hercules’s two great globular star clusters. In binoculars it’s a tiny glowing cotton ball.

Skywatch Line for Wednesday and Thursday, May 24 and 25, 2023

This is Dudley Observatory’s Skywatch Line for Wednesday and Thursday, May 24 and 25, written by Alan French.

The Sun rises at 5:38 A.M. on Wednesday and sets at 8:06 P.M. On Thursday it rises at 5:37 and sets at 8:07. This Thursday has just under 12 ¾ minutes more daylight than last Thursday.

The Moon is moving toward first quarter and is toward the west as darkness falls. On Wednesday night at 9:30 P.M. the 26% illuminated crescent will be toward the west, with brilliant Venus 16 ½ degrees to its lower right. Much fainter, reddish Mars will be just below the Moon, 4 degrees away. Just over 4 degrees to the left of the Moon, and slightly lower at 9:30, is the famous Beehive, a large star cluster known since ancient times. It’s nicely visible to the unaided eye under dark skies, but the nearby Moon’s light will probably mean you’ll need binoculars to spot the cluster.

By Thursday night at 9:30 P.M. the Moon will be 35% in sunlight and the Beehive almost 10 degrees to the Moon’s lower right.

There’s an interesting pass of the ISS (International Space Station) on Wednesday night. We see satellites because they are still up in sunlight while we are down in the Earth’s shadow. If the timing is right, we can sometimes see a satellite move into the shadow and fade from view. We have such a chance Wednesday night.

Look for the ISS coming up from the west northwestern horizon just after 11:00 P.M. It will pass to the right of Venus and at 11:01:30 (HH:MM:SS) will be passing to the right of Castor and Pollux, a pair of equally bright stars in Gemini. By 11:03 it will be obvious the ISS is headed toward the Big Dipper. Before 11:04 it will be moving through or close to the Dipper’s bowl, depending on where you are in the Capital District. Just after it exits the bowl or its vicinity, the ISS will move into the Earth’s shadow and fade from view. How far can you follow it before it vanishes completely?

Thursday night’s ISS passes stays lower in the sky. It is earlier in the evening so more of the sky overhead is in the Earth’s shadow, so the ISS is visible for a longer part of it journey overhead.

Look for the ISS low in the northwest at 10:12 P.M. By 10:13 it will be passing above Capella, a bright star low in the northwest. The path of the space station will take it across the northern sky and at 10:15 it will pass just above Polaris, the North Star. It will pass through the Little Dipper and the head of Draco, the Dragon. Just after 10:16 it will pass above Vega in the east northeast, the brightest star in Lyra. Shortly afterwards, when in the east, it will move into the Earth’s shadow and fade away.

Skywatch Line for Monday and Tuesday May 22nd, and 23rd, 2023

This is the Dudley Observatory’s Skywatch Line for Monday and Tuesday May 22nd, and 23rd, written by Joe Slomka.

The Sun sets at 8:18 PM; night falls at 10:23. Dawn begins at 3:23 AM and ends with the Sun rising at 5:27

Gemini houses both waxing Moons. Monday’s rises in the Northwest at 7:17 AM, 25° high at 9 PM, almost 30° in size, 12% illuminated and sets at 11:45 PM. Tuesday’s Western Moon, rises at 8:14 AM, the same size, but 18% lit and sets at 12:29 AM on Wednesday. On both days, the observer can use the Moon to find Venus and Mars before Sunset.

Venus also abides in Gemini, is the first evening planet, blazes with minus 4th magnitude, 20 arc-seconds, 28° high at 9 PM, 56% lit and sets at 11:49 PM. Mars, now in Cancer, follows 12° below Venus, glows with 1st magnitude, 4 arc-seconds, 37° high at 9 PM and sets at 12:35 AM. Mars, Venus and the Moon form a straight line on Monday.

Dwarf Plant 1Ceres still lies 2.5° from Leo’s tail – the star Denebola. It glows with 8th magnitude, a tiny 0.6 arc-second, 97% lit, rises at 2 PM, highest at 8:54 PM, sets at 3:51 AM and is 60° high in the South.

All early rising planets set during daytime. Southeastern Saturn is the first Dawn planet, rising in Aquarius, shines with 1st magnitude, almost 17 arc-seconds, rises at 2:11 AM and 27° high at 5 AM. Neptune follows, in Pisces, 8th magnitude, 2 arc-seconds, rises at 2:56 AM, 22° high and 21° from Saturn.

Jupiter and Mercury share Aries. Jupiter rises at 4:13 AM, a large 34 arc-seconds, 9° high and 34° from Neptune. Mercury is close to the eastern horizon; it rises at 4:41 AM, shines with 1st magnitude, 9 arc-seconds, but only 3° from the Sun, making finding the elusive plant difficult.

Most people know that Mercury is the planet closest to the Sun. Over 150 years ago, that was not certain. Urbain Leverrier, a French astronomer, had just discovered the planet Neptune by analyzing oddities in Uranus’ orbit and using Newton’s laws. Astronomers knew of similar problems with Mercury’s orbit. Some issues were solved, again using Newton’s laws, but others remained unexplained. Leverrier took up the challenge and predicted that a planet could exist between the Sun and Mercury, if it had a specified orbit. In 1859, a French amateur astronomer, Edmond Lescarbault, claimed to have spotted it. Leverrier interviewed Lescarbault, proclaimed his discovery real and appropriately named the new planet “Vulcan” after the Roman god of fire. However, another French astronomer named Liais was observing in Brazil at the same time as Lescarbault and did not see it. Other reports had similar mixed results. Two New York astronomers, Lewis Swift and Christian Peters (who once headed Dudley Observatory) observed during an eclipse in 1878. They failed to find Vulcan, only sunspots. In 1915, Albert Einstein solved the mystery and discredited Vulcan. His Theory of Relativity predicted that Mercury’s orbital precession was due to Relativity effects. Several space probes now orbit the Sun and provide constant imagery; no new planet has been observed.

Skywatch Line for Friday, May 19, through Sunday, May 21, 2023

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

On Friday, Sun rises at 5:29am and sets at 8:15pm; Moon rises at 5:14am and sets at 8:41pm. New Moon occurs at 11:53am on Friday.

Venus, magnitude –4.3, is passing Pollux and Castor in Gemini. Venus is the brilliant “Evening Star” in the west from twilight through late evening. This month it shines about as high in the dusk as it ever gets. It doesn’t set until about 2½ hours after dark. In a telescope Venus is a little gibbous globe, 60% sunlit and 19 arcseconds in diameter. It’s enlarging a little more every day while waning in phase.

Mars glimmers near Pollux and Castor, upper left of Venus. Mars has faded to magnitude +1.5, a bit dimmer than Pollux and practically as faint as Castor. From left to right, Mars is orange, Pollux is paler yellow-orange, and Castor is white. Watch their configuration change daily.

Jupiter is beginning to emerge very low in the sunrise. Look for it very low in the east in the brightening dawn about 30 minutes before sunrise.

Saturn, magnitude +1.0, in dim constellation of Aquarius, is low in the southeast before and during early dawn.

Summer is still a month away, but the Summer Triangle is making its appearance in the east, one star after another. The first in view is bright Vega. It’s already visible low in the northeast as twilight fades. Vega is now nicely up in the east-northeast after dark. Look for its faint little constellation Lyra, the Lyre, hanging down from it with its bottom tilted to the right. Lyra’s stars form a little equilateral triangle, with Vega in one corner, and a parallelogram attached to the triangle’s bottom.

Next up of the Summer Triangle is Deneb, in the constellation of Cygnus, the Swan. Deneb is in the lower left of Vega by two or three fists at arm’s length. Deneb takes about an hour to appear after Vega does.

The last star of the Summer Triangle doesn’t rise above the eastern horizon until about 11 p.m. That’s Altair, in the constellation of Aquilla, the Eagle. Altair makes the Triangle’s lower right corner. Watch for Altair to clear the horizon three or four fists at arm’s length to Vega’s lower right. Deneb sits less far to Vega’s lower left.

This is the time of year when Leo, the Lion, starts moving downward toward the west right after dark, on his way to departing into the sunset in early summer. After nightfall, spot Regulus, the brightest star high in the west-southwest. Regulus is Leo’s forefoot.

Regulus is also the bottom of the Sickle of Leo, a backward question mark about a fist and a half tall that outlines the lion’s leading foot, chest, and mane.

Skywatch Line for Monday and Tuesday May 15th, and 16th, 2023

This is the Dudley Observatory’s Skywatch Line for Monday and Tuesday May 15th, and 16th, written by Joe Slomka.

The Sun sets at 8:11 PM; night falls at 10:11. Dawn begins at 3:32 AM and ends with the Sun rising at 5:32.

Monday’s waning Moon rose, in Cetus, at 3:39 AM, visible during daylight, in the Southwest, 36° high at Noon, 18% illuminated and sets at 3:52 PM. Tuesday’s Moon shifts to southern Pisces, rising 4:01 AM, same size, 10% lit, 47° high at Noon and sets at 5:05 PM.

Gemini houses western Venus and Mars. By 9 PM, Venus blazes with minus 4th magnitude, 19 arc-seconds, 60% lit and sets at 11:48 PM. Mars, 18° to Venus’ left, glows with 1st magnitude, 5 arc-seconds, 40° high and sets at 12:50 AM. Dwarf Planet 1Ceres, in Leo, glimmers with 8th magnitude, 0.6 arc-seconds, 97% lit, 61° high and sets at 4:21 AM. It is found 2° to the left of Leo’s tail, the star Denebola.

Saturn, in southeastern Aquarius, is the first star to rise during Dawn at 2:38 AM; it glimmers with 1st magnitude, 16 arc-seconds and 23° high at 5 AM.

Jupiter and Neptune share Pisces. Neptune, in the Southeast, glimmers with 8th magnitude, 18° high at 5 AM, rises at 3:23 AM. Neptune is sandwiched between Saturn and the Moon. Finally, eastern Jupiter rises in Pisces at 4:36 AM, sparkles with minus 2nd magnitude, a large 33 arc-seconds, 5° high at 5 AM and 15° from Neptune. Wednesday, Jupiter can be found very close to the last easily spotted Moon.

The Albany Area Amateur Astronomers hold their monthly meeting on the 18th at 7:30 PM in miSci. This month’s guest speaker is Dr. Mindy Townsend who discusses the “Feed Me Seymour” – Evolution of Massive Galaxies. As usual, all club events are free and open to the public.

Venus is the second planet from the Sun, almost an Earth twin, about the same size and slightly less mass. Early telescopic observers noted its complete cloud cover. They speculated that Venus was a lush, tropical planet. As science obtained better instruments, rude shocks came. Venus did not rotate in 24 hours like Earth; its day lasts 243 earth-days. Russian and US probes landed on Venus; pictures showed a rock filled wasteland. Those same probes recorded a toxic atmosphere with acid rain. Since Venus is closer to the Sun, it gets twice the solar radiation. Temperatures approach the melting point of lead and atmospheric pressure is 90 times that of Earth. Its slow rotation and lack of axis tilt means no seasons or weather. Most planetary scientists now think that Venus is a case of uncontrolled global warming. Oceans boiled off, leaving an atmosphere of 96 percent carbon dioxide. Without oceans, there was no water to capture the carbon dioxide into limestone rocks, as on Earth.

Space probes revealed strange behavior. Mid-latitude winds race around the planet in four days. Russian and Japanese independent observations found that winds sped up from 180 MPH to 250 in six years. Japanese researchers also discovered that winds vary about 45 MPH over 250 days, while the Venusian year is only 225 days.

Skywatch Line for Friday, May 12, through Sunday, May 14, 2023

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

On Friday, Sun rises at 5:36am and sets at 8:08pm; Moon rises at 2:23am and sets at 12:07pm. Last-quarter Moon occurs at 10:28am on Friday. The Moon rises a few minutes before 3:00am Saturday, with Saturn glowing a few degrees to its upper left. As dawn begins on Saturday, they’re higher and easier to see.

Venus, magnitude –4.2 near the feet of Gemini, is the brilliant “Evening Star” in the west from twilight through late evening. This month it shines about as high in the dusk as it ever gets. It doesn’t set until a good 2½ hours after dark. In a telescope Venus is a dazzling little gibbous globe, 62% sunlit and 18 arcseconds in diameter. It’s enlarging a little more every day while waning in phase.

Mars is crossing the constellation of Gemini. It sits about 2 fists at arm’s length upper left of Venus. Much closer to Mars’s upper right or right are Pollux and Castor. Mars has faded to magnitude +1.4, between Pollux and Castor in brightness. Mars is orange, Pollux is paler yellow-orange, and Castor is white. Watch their configuration change daily. Mars is nearly on the far side of its orbit from us. In a telescope it’s just a tiny blob 5 arcseconds wide.

Saturn, magnitude +1.0 in dim Aquarius, is low in the southeast before and during early dawn.

The Great Diamond is a gigantic asterism, some 50° tall and extending over five constellations. It now stands upright in the southeast to south after dusk. Start with Spica, its bottom. Upper left from Spica is bright Arcturus. Almost as far upper right from Arcturus is fainter Cor Caroli, 3rd magnitude. The same distance lower right from there is Denebola, the 2nd-magnitude tail-tip of Leo. Then back to Spica. Robert H. Baker may have been the first to name the Great Diamond, in his 1954 book When the Stars Come Out. The bottom three of Great Diamond stars, the brightest, form a nearly perfect equilateral triangle. These stars are called the “Spring Triangle” to parallel to those of summer and winter. The first to name it such was probably the late Sky & Telescope columnist George Lovi.

On these moonless spring evenings, use the Great Diamond to find the big, dim Coma Berenices star cluster. It’s one of the nearest clusters at about 280 light-years, which accounts for its apparent size. If you have a dark sky, or binoculars, look halfway from Cor Caroli to Leo’s tail-tip Denebola to locate the star cluster. It spans some 4°, about the size of a ping-pong ball held at arm’s length. Its brightest stars form an upside-down Y of an asterism.

Use binoculars or a telescope to spot the globular cluster M5, the Serpent’s Gem, in Serpens Caput high in the southeast as evening grows late. At magnitude 5.6, it’s easy to see with binoculars in a moderately dark sky if you know where to look.

Skywatch Line for Wednesday and Thursday, May 10 and 11, 2023

This is Dudley Observatory’s Skywatch Line for Wednesday and Thursday, May 10 and 11, written by Alan French.

The Sun rises at 5:38 A.M. on Wednesday and sets at 8:06 P.M. On Thursday it rises at 5:37 and sets at 8:07. This Thursday has just under 16 ½ minutes more daylight than last Thursday.

The Moon was full last Friday and is now headed toward last quarter, which it reaches this coming Friday morning. A waning gibbous Moon does not rise until after midnight, leaving the evening skies moonless and dark. If you’re up just before sunrise Thursday look for a 64% sunlight Moon low toward the south southeast. By Friday morning before sunrise, it will be just over half illuminated and farther toward the south. The gibbous Moon will move low across the southeastern sky during the daylight, morning hours.

Venus continues to dominate the evening sky and is now north of west. At 10:00 P.M. our size twin is still 17 degrees high and in the north northwest, brilliant at magnitude -4.2 and quite stunning against the twilight free skies, especially if you are away from city lights.

High in the north is a familiar pattern of stars, the Big Dipper. If its pattern escapes you briefly, it is upside down, with the bowl open toward the Earth. The handle stretches off toward the right.

The Big Dipper’s stars are part of the stars of Ursa Major, the Great Bear. The outline of the bear is fairly easy to picture in our sky, the problem is that when the bear is right side up it is low in the north and the bear’s legs are often hidden by trees or hills. When the bear is upside down and high in the sky, you can easily see the entire bear.

Unlike real bears, our sky bear has a long tail, represented by the three stars of the dipper’s handle. The dipper’s bowl outlines the back half of his body. Another pair of stars, about as far in front of the bowl as its length, mark the bear’s shoulders. A single star farther away from the bowl marks his nose.

The bear’s legs stretch upward. A line of stars, quickly spitting in two, both curving leftward from his hind quarters, outline two rear legs. Another line of stars, also curving leftward from his shoulder, forms one of his front legs.

Ursa Major, a large and sprawling constellation, is the third largest constellation, only slightly outdone by Virgo and Hydra, with Hydra the largest of the 88 officially recognized constellations. The seventeen largest constellations all have ancient roots, the largest modern constellation is Camelopardalis, the Giraffe, added by Dutch theologian and astronomer Petrus Plancius in 1612. It was formed between the head of the Great Bear and Cassiopeia, a region lacking bright stars and left blank by the Greeks.

Skywatch Line for Monday and Tuesday May 8th, and 9th, 2023

This is the Dudley Observatory’s Skywatch Line for Monday and Tuesday May 8th, and 9th, written by Joe Slomka.

The Sun sets at 8:04 PM; night falls at 9:59. Dawn begins at 3:45 AM and ends with the Sun rising at 5:40.

Sagittarius hosts the Moon on both nights. Monday’s waning Moon rises in the southeast at 11:59 PM, 86% illuminated, 32 arc-minutes in size, 20° highest at 4 AM and sets at 8:23 AM, on Tuesday. The Moon rises, on Wednesday, at 12:58 AM, same size but 76% lit, 21°highest at 5 AM and sets at 9:41 AM.

Venus and Mars continue to be the only visible planets in the evening, sharing Gemini on both nights. Although Mars is first to rise, Venus is easier to spot. In the West, it blazes with minus 4th magnitude, 18 arc-seconds, 63% lit, 16°high at 9 PM and sets at 11:42 PM. Mars lies 21° to Venus’ lower left and continues to shrink and dim. By 9 PM, it glows with 1st magnitude, 5 arc-seconds, 43°high and sets at 1:05 AM. Monday, it lies 5°South of Pollux and 5.2°on Tuesday.

Dwarf Planet 1Ceres lies 2° from Leo’s tail – Denebola, glows with 7th magnitude, a tiny 0.6 arc-seconds, rises at 1:53 PM, 64°highest at 8:48 PM, 97% lit and sets at 3:48 AM.

Uranus experiences “conjunction” (closest) with the Sun and not visible. Mercury was in conjunction but is slowly leaving the Sun and also not observable.

Three planets occupy the brightening dawn sky and all set during daytime. Southeastern Saturn remains the first, in Aquarius, rises at 3:04 AM, smolders with 1st magnitude, 16 arc-seconds and 29°high at 5 AM. Jupiter shares Pisces with Neptune. Southeastern Neptune glimmers with minus 8th magnitude, 2 arc-seconds, rises at 3:50 AM and is 24°; high at 5 AM. Jupiter, although brightest, is more difficult to spot, lying 20°from the Sun. It shimmers with minus 2nd magnitude, a large 33 arc-seconds and rises at 5 AM.

Giovanni Schiaparelli was an Italian astronomer, born in 1835. He studied under eminent astronomers and was made director of the Brera Observatory of Milan in 1860. He is recognized for discovering that meteor showers originate from comets. But is most famous for his drawings of “canals” on Mars. In 1877, he called perceived markings on Mars “canali” “channels” However, the English translation became “canals” which imply mechanical constructions. This announcement electrified the world, including Percival Lowell. A millionaire, Lowell used his fortune to establish a state-of-the-art observatory in Flagstaff, Arizona, with the intent of studying these “canals” Lowell’s observations not only agreed with Schiaparelli’s, but also amplified them. Lowell wrote popular magazine articles, depicting Mars as a dying planet, whose inhabitants were desperately digging canals to water their farms. By the 1920s, observations by other astronomers debunked these notions. In the 1960s, spacecraft sent back pictures of Mars as a desert without any “canali.” American robots prowl the Martian surface and failed to find any canals, but have found traces of water on the now arid planet. Schiaparelli and Lowell’s “canals” are now considered to be artifacts, caused by the brain’s attempt to make sense out of unfamiliar sights.