Skywatch Line for Monday, and Tuesday, January 27th and 28th, 2020

This is the Dudley Observatory Skywatch Line for Monday, and Tuesday, January 27th and 28th, written by Joe Slomka.

The Sun sets at 5:01 PM; night falls at 6:39. Dawn breaks at 5:36 AM and ends with the Sun rising at 7:14.

The Moon and Venus, both in Aquarius, dominate the early evening sky. Monday, Venus blazes with minus 4th magnitude high in the southwest, appears about 15 arc-seconds in size and appears about 75% illuminated. The waxing Moon lies about 6° below Venus, appears about one half degree in size and 9% illuminated. The Moon sets at 7:49 PM on Monday. Tuesday, Venus now appears about 4° north of the Moon, which now appears about 16% lit and sets at 8:49 PM. Venus sets at 8:19 PM.

One hour past Monday’s sunset, Neptune, also in Aquarius, appears less than 1° below Venus, shining with 8th magnitude, 12 magnitudes fainter than Venus, and about 2 arc-seconds in size; Neptune sets at 8:18 PM. Tuesday, Mercury, in Capricornus, may be spotted with difficulty. It lies very low in the southwest, shines with minus 1st magnitude, appears 92% lit, and sets at 5:51 PM; elusive Mercury probably requires an unobstructed southwestern horizon.

Nightfall also reveals Uranus, in Aries, brighter with 6th magnitude, 3 arc-seconds in size and sets at 12:26 AM. Finder charts for Neptune and Uranus can be found in astronomy magazines and websites.

The Dawn sky is becoming crowded. Mars rises in Ophiuchus at 4:01 AM. The Red Planet shines with 1st magnitude and appears about 5 arc-seconds in size. It still close enough to Antares in Scorpius for comparisons between the two red rivals. Jupiter rises about 5:56 in Sagittarius, shining with minus 1st magnitude and appearing a large 32 arc-seconds in size. It should be bright and large enough to be seen by the naked eye about 7 AM. Saturn, also in Sagittarius, rises at 5:56 AM, shining with zero magnitude and appears half Jupiter’s size

Throughout the night, star clusters abound. In early evening, we find the Pleiades above the shoulders of Taurus. The Bull’s face is made of another star cluster, the Hyades. The nearby constellation Auriga harbors three clusters. Finally, Cancer contains the Beehive and M 67.

All these are called “Open Clusters.” They appear to contain, at most, a few hundred stars, which are widely spaced and irregularly shaped. Open clusters are relatively young, less than a billion years old. They reside in the disk of a galaxy and are relatively small, about 50 light-years across.

There is another class of star clusters. These are called “Globular Clusters.” Globular clusters are usually found around galaxy halos and central bulges. Globulars may contain up to a million stars and are quite large, in a sphere about 100 light-years across. These stars are quite old.

If tonight’s weather is clear, binoculars can show many Open Clusters. Just dress warmly and observe the Hyades, Pleiades and the nearby pentagon shaped constellation Auriga.

Skywatch Line for Friday, January 24, through Sunday, January 26, 2020

This is Dudley Observatory’s Skywatch Line for Friday, January 24, through Sunday, January 26, written by Sam Salem.

On Friday, Sun rises at 7:18am and sets at 4:58pm; new Moon occurs at 4:42pm. The new Moon crosses the sky with the Sun, therefore, it remains hidden in star’s glare.

Mercury returns to the evening sky. If you have a clear sky and an unobstructed horizon toward the west-southwest, you should be able to glimpse it through binoculars. Mercury lies just 2 degrees high, 30 minutes after the Sun goes down on Saturday. Fortunately, you’ll have some help spotting it. The thin crescent Moon appears just 2 degrees to the left of the magnitude –1.1 planet. You’ll have only about 10 minutes to catch them before they sink out of sight.

On Sunday evening, use Venus to guide you to the solar system’s outermost planet, Neptune. You will need binoculars or a telescope to spot the 7.9 magnitude distant planet. Target Venus with binoculars or a telescope at low power, about 90 minutes after sunset. Note the 4th-magnitude star Phi (φ) Aquarii 1.4 degrees above it. Neptune lies two-thirds of the way from Venus to Phi. Don’t confuse the outer planet with a slightly brighter star that stands 0.5 degrees to its right. Through a telescope, Venus appears 15″ across and three-quarters illuminated while Neptune shows a 2.2″-diameter disk colored blue-gray. The two planets will appear even closer to each other on Monday night.

Jupiter disappeared from our evening sky late last year. Now Jupiter has returned to the east before sunrise. Mars is also in the east, easily visible to the eye before dawn right now. However, Mars isn’t nearly as bright as Jupiter. Mars and the nearby red star Antares might fade from view by the time Jupiter rises in sky. You’ll need an unobstructed horizon in the direction of sunrise and you might need binoculars to be able to spot Jupiter close to the horizon in the hazy murk of dawn.

The nighttime’s brightest star, Sirius, shines at magnitude -1.5. Nearly four times brighter than the next brightest star, Arcturus in the constellation Boötes. Sirius is easy to see because it’s so bright and because the three prominent Belt stars in the constellation Orion the Hunter always point to it. Sirius rises shortly after sunset and climbs highest in the south by late evening. Look for Sirius, and the faint star cluster near it. That fuzzy spot near Sirius isn’t a comet. It’s the lovely star cluster called Messier 41 or M41. This cluster lies about four degrees almost exactly south of Sirius. M41 is sometimes also called the Little Beehive, after the other famous Beehive star cluster (M44), also an open cluster, in the constellation Cancer. Sirius and M41 stay out until roughly 3am.

Right after dark, face east and look very high for Capella, the brightest star of constellation Auriga the Charioteer. While Capella appears as a single star to the naked eye, it actually is a group of four stars, two large binary stars, and two fainter binary dwarfs. It has been identified as a source of X-rays, likely because of the strength of its corona or surrounding gas envelope. To the right of Capella, by a couple of finger-widths at arm’s length, is a small, narrow triangle of 3rd and 4th magnitude stars known as Haedi, or “the Kids.” Though they’re not exactly eye-grabbing, they form a nice asterism with Capella. The asterism was a separate constellation until Ptolemy merged it with the Charioteer constellation Auriga in his Almagest in the 2nd century.

Skywatch Line for Wednesday, January 22nd, and Thursday, January 23rd, 2020

This is the Dudley Observatory Skywatch Line for Wednesday, January 22nd, and Thursday, January 23rd, written by Louis Suarato.

The 5% illuminated, waning crescent Moon sets at 2:59 p.m., Wednesday. It will rise again, 2% illuminated, at 6:36 a.m., Thursday. Jupiter joins our two neighbors, Venus and Mars, as viewable planets. Jupiter has completed its trek from behind the Sun to once again appear in our pre-dawn sky. Use binoculars to look for Jupiter about 6 degrees above the crescent Moon after it rises above the southeastern horizon at 6:08 a.m., Thursday. Mars will be to Jupiter’s upper right, about 20 degrees above the south-southeastern horizon. Venus is 75% illuminated and shines at magnitude -4.1 about 25 degrees above the southwestern horizon after sunset. Venus sets at 8:11 p.m., Thursday.

These moonless, winter nights provide an opportunity to clearly view spectacular binocular targets. Winter skies are too cold to retain moisture, and therefore provide a clearer view than the hazier skies during warmer weather. Also, during these winter months, constellations containing these binocular targets are in a high position during the early evening hours, and void of atmospheric interference. Taurus is a constellation that meets these conditions. By 7 p.m., Taurus’ brightest star, Aldebaran is 53 degrees above the southeastern horizon. Look about 20 degrees (two fists held at arm’s length) above Aldebaran for the Pleiades Star Cluster, also known as the Seven Sisters. This open cluster of stars is entirely enclosed by nebulosity which reflects the component’s starlight. A binocular view of the Pleiades will reveal a dipper-like shape of stars. These young stars are approximately 440 light-years away. Dozens of stars can be seen through binoculars, while hundreds can be seen through small telescopes. Below the Pleiades, and closer to Aldebaran, is another open star cluster known as the Hyades. This V-like shape of stars is about 150 light-years away. Dozens of the stars within the Hyades can be seen through binoculars, of which more than 130 are brighter than 9th magnitude. Former Dudley Observatory Director, Lewis Boss, was the first to demonstrate the stars of the Hyades drift together through a space toward a point a few degrees east of Betelgeuse in Orion.

Skywatch Line for Monday, and Tuesday January 20th and 21st, 2020

This is the Dudley Observatory Skywatch Line for Monday, and Tuesday January 20th and 21st, written by Joe Slomka.

The Sun sets at 4:53 PM; night falls at 6:32. Dawn begins at 5:41 AM and ends with the Sun rising at 7:20.

Venus is the only easily visible planet in our evening sky. In Aquarius, it blazes with minus 4th magnitude, and appears about 14 arc-seconds in size, 5° high in our binoculars and telescopes and about 75% illuminated; it sets at 8:02 PM.

Nightfall reveals Neptune in Aquarius, shining with 8th magnitude, about 2 arc-seconds in size and 13° high; it sets at 8:44 PM. Uranus, in Aries, appears above Venus shining with 6th magnitude, a bit larger and about 53° high; it sets at 12:45 AM. Finder charts for both are available from astronomy magazines and websites.

The waning Moon does not appear on Monday evening; it rises at 4:34 AM, Tuesday, in Ophiuchus. It appears about 31 arc-minutes in size and about 13% illuminated and sets at 2 PM. The Moon rises in Sagittarius at 5:36 AM, Wednesday, appearing 11° high and setting at 2:50 PM.

Mars rises in pre-dawn Ophiuchus at 4:05 AM, glowing with first magnitude and 4.6 arc-seconds in size. Mars continues to slowly brighten and enlarge. The Red Planet is joined by Jupiter, when it rises in Sagittarius at 6:18 AM, blazing with minus 1st magnitude, a large 32 arc-seconds in size, but a low 2° above the horizon, requiring an unobstructed view.

Tuesday and Wednesday reveal a dramatic pre-sunrise sky scene. Tuesday, at about 5:30 AM, the Moon and Mars rise virtually together near the star Antares, followed by Jupiter 40 minutes before sunrise. Wednesday, Mars and Antares rise, followed by the Moon and then Jupiter. Early observers should also study Mars and the nearby red star Antares in Scorpius. The word “Antares” is usually translated as “the Rival of Mars.” Note that they indeed look alike. However, Antares is red because it is a giant, bloated, old star, while Mars is red because its soil is rust colored and rusty!

As mentioned last week, Sirius B, or “The Pup” was the first discovered White Dwarf star. But what is a “white dwarf?”

White Dwarfs are the dead cores of Sun-like stars. These stars, toward the ends of their lives, shed layers until all that is left are the exposed dead interiors of dying stars. They no longer fuse hydrogen, but shine from leftover heat, are mostly carbon, and slowly cool down. These dead centers have the mass of a Sun-like star, but compressed into Earth size. Many planetary nebulae, like the Ring Nebula in Lyra, have white dwarfs in the center. They are normally not very bright, but shine in ultraviolet or X-Rays. Some white dwarfs are members of binary systems. These dwarfs steal material from their larger companions and become reenergized. The accumulated hydrogen precipitously flashes; the result is a “nova,” which suddenly brightens in the night sky. Some binary white dwarfs exceed the “white dwarf limit,” and blow themselves apart as White Dwarf Supernova. White Dwarf Supernovae are called Type I supernovae; Type II are giant stars exploding themselves apart. Type I supernovae act as “standard candles,” which enable astronomers to estimate the distance to galaxies.

Skywatch Line for Friday, January 17, through Sunday, January 19, 2020

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

On Friday, Sun rises at 7:23am and sets at 4:49pm; Moon sets at 11:39am. By the time last quarter Moon rises on Friday night around 1am, it will be at the dim feet of constellation Virgo, then, with Spica to its upper right and bright Arcturus higher to its upper left.

On Friday morning, locate planet Mars, 5 degrees above the ruddy star Antares.
Before dawn on Sunday and Monday, look for the waning crescent Moon in the neighborhood of planet Mars and Antares. On Monday before dawn, note that the Moon has moved some 13 degrees, or 26 moon diameters, closer to Mars and Antares. Mars is modesty-bright right now, only two-thirds the brightness of the 1st-magnitude Antares. The name Antares is derived from the Ancient Greek, meaning “rival to-Ares”, or opponent to-Mars, due to the similarity of its reddish hue to the appearance of planet Mars. Antares, or α Scorpii, is the brightest object in Constellation Scorpius.

Venus, at magnitude –4.0, dominates the southwest during and after twilight. Venus lies between constellations Capricornus and Aquarius. It will shine as the “Evening Star” at dusk all winter and into the spring. In a telescope Venus still appears small (14 arc-seconds) and gibbous (78% sunlit). But it will enlarge in size and wane in phase for the next 4 months.

Jupiter is buried deep in the glow of sunrise. But in the next few mornings, you can use the waning crescent Moon to locate Jupiter in the sky. The lit side of the lunar crescent points in the direction Jupiter. You’ll need to find an unobstructed horizon in the direction of sunrise. Also, you might need binoculars to spot Jupiter close to the horizon in the hazy murk of dawn.

If your sky is dark enough you can see the winter Milky Way this weekend. In mid-evening, the Milky Way runs vertically up and across the zenith from Canis Major low in the southeast, up between Orion and Gemini, through Auriga and Perseus almost straight overhead, and down through Cassiopeia, Cepheus, and Cygnus to the northwest horizon.

One of the sky’s most familiar constellations, Orion the Hunter appears in the southeast after darkness falls and climbs highest in the south around 10pm. It then stands about halfway to the zenith. Orion rules January’s sky from dusk until near dawn. If you’ve watched Orion over the years, you might notice that it doesn’t look quite the same now. Ruddy Betelgeuse, which marks one of the Hunter’s shoulders, currently glows about a magnitude fainter than normal. Astronomers are still trying to figure out why this known variable star has dimmed to its faintest level in more than a century.

Sunday marks the 273rd. Birthday of the German Astronomer Johann Elert Bode, best known for his popularization of Bode’s law. Bode was director at the Berlin Observatory. In 1766, his compatriot Johann Titius had discovered a mathematical relationship in the distances of the planets from the Sun. The formula suggests that, extending outward, each planet would be approximately twice as far from the Sun as the one before. If 4 is added to each number in the series 0, 3, 6, 12, 24,… and the answers divided by 10, the resulting sequence gives the distances of the planets in astronomical units (earth = 1). This mathematical relationship is known as the Titius-Bode law. The hypothesis correctly anticipated the orbits of Ceres, in the asteroid belt, and Uranus, but failed as a predictor of Neptune’s orbit.

Skywatch Line for Wednesday, January 15th, and Thursday, January 16th, 2020

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

After sunset, look for -4.0 magnitude Venus about 23 degrees above the southwestern horizon. Venus will set at 7:55, Wednesday night. The 66% illuminated, waning gibbous Moon rises at 10:27 p.m. Wednesday, in the constellation Virgo. The bright, first magnitude star, Arcturus, rises with the Moon about 30 degrees to its northeast. Arcturus, also known as Alpha Bootis, is a red giant star in the constellation Bootes, and the brightest star in the northern celestial hemisphere. Arcturus, along with Spica in Virgo, and Denebola, in Leo, form the asterism known as the Spring Triangle. When Cor Caroli, in Canes Venatici is added, the four stars form an asterism known as the Great Diamond. To find Arcturus, follow the arc of the Big Dipper. Mars rises at 4:04 a.m. in the constellation Scorpius.

Asteroids are remnants remaining from the planet forming era about 4.6 billion years ago. Of the 930,749 known asteroids, most are located in an orbit between Mars and Jupiter. This section of our solar system is known as the Asteroid Belt. Asteroids, also called minor planets, or planetoids, differ from comets in composition. Unlike comets, which are made up of ice and dust, Asteroids are comprised of minerals and rock. Once thought to be debris from a planet’s demise, the asteroid belt is now believed to be the beginning of what could have been planets, had it not been for Jupiter’s strong gravitational influences. Jupiter’s gravitational pull is also believed to be a shield protecting Earth from incoming asteroids. A recent study by Kevin Grazier suggests that Jupiter may also be responsible for sending asteroids our way. Grazier collaborated with NASA’s Jet Propulsion Laboratory to develop simulations proving his theory. The website lists recent and upcoming Earth-asteroid encounters. According to this website, as of 1/12/2020, there were 2,018 Potentially Hazardous Asteroids (PHA’s). A chart is provided by the webpage giving the name, date of closest encounter, distance, velocity, and diameter of the PHA.

Skywatch Line for Monday, and Tuesday, January 13th and 14th, 2020

This is the Skywatch Line for Monday, and Tuesday, January 13th and 14th, written by Joe Slomka.

The Sun sets at 4:44 PM; night falls at 6:24. Dawn begins at 5:44 AM and ends with the Sun rising at 7:24.

The Moon occupies Leo on both nights. Monday’s Moon rises at 8:15 PM appears about 87% illuminated and sets at 10:12 AM, Tuesday. Tuesday’s Moon rises at 9:30 PM, is 79% lit and sets at 10:42 AM, Wednesday. Monday’s Moon is at perigee (closest to Earth), which means it is about 227, 396 miles away; it is also quite close to Leo’s brightest star, Regulus.

Venus is the only bright planet during evening. In Aquarius, it blazes with minus 4th magnitude and appears about 14 arc-seconds in size. This month Venus gains altitude from about 27° to 34° at month’s end; it sets at 7:45 PM.

Nightfall brings out Neptune and Uranus. Neptune, also in Aquarius, glows with 8th magnitude, appears a tiny 2 arc-seconds in size, is moderately high in the West and sets at 9:11 PM. Uranus, still occupying Aries, shines with 6th magnitude, about 4 arc-seconds big and sets at 1:13 AM. Finder charts for these planets are available from astronomy magazines and websites.

Mars is the only visible Dawn planet. It rises about 3 hours before the Sun at 4:09 AM, shining with 1st magnitude, growing to about 4 arc-seconds and sets at 1:20 PM. Mercury is in the sky, but too close to the brilliant just risen Sun.

Planets are considered to be in Superior Conjunction when they pass behind the Sun, from Earth’s view. Monday, Saturn makes a rare trip behind the Sun, followed by Pluto, two hours later. Of course, both are hidden by our Sun and will become visible later this year.

As the Sun sets, the giant constellation Orion appears. Canis Major, the Big Dog, follows at Orion’s heels. Sirius, the Dog Star, is among the closest stars to our Solar System, at 8.6 light-years. Although stars seem fixed in our sky, they are actually traveling in different directions and speeds. Sirius is one of these. In sixty thousand years, it will approach to 7.8 light-years and increase its brightness only marginally. Sirius is not a solitary star; it has a companion, appropriately nicknamed “The Pup.” This star closely orbits Sirius once every fifty years. This star is much smaller and dimmer than the primary. Sirius B, as this star is formally called, is still a bit too close. In a few years, amateur telescopes may spot The Pup, once Sirius’ brilliance is blocked. Sirius B is about the Earth’s size, but has the Sun’s mass.

Skywatch Line for Friday, January 10, through Sunday, January 12, 2019

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

On Friday, Sun rises at 7:26am and sets at 4:41pm. Full Moon occurs on Friday at 2:21pm; the full Moon rises at 4:38pm and sets at 7:20am. Full Moon rises almost at sunset and sets at sunrise. The position of the ecliptic on winter nights causes January Moon to culminate very high in the night sky. This full Moon will occur while the Moon is partially on the ecliptic, producing a penumbral lunar eclipse. The entire eclipse will be visible from Europe, eastern Africa, and Asia. Parts of northern Canada and the Maritimes will only see the beginning and final stages of the eclipse.

On Saturday evening, bright Moon rises in the northeastern evening sky. It will be sitting very close to the left side of the large open star cluster Beehive. The brightest deep sky cluster in constellation Cancer is also called Messier 44. The Moon and the cluster will both fit within the field of view of binoculars. The bright moonlight will obscure the cluster’s dimmer stars. Place the Moon just outside of the left edge of your binoculars’ field of view and look for the cluster’s stars.

On Saturday, the blue-green planet Uranus will temporarily cease its motion through the distant stars of southwestern constellation Aries the Ram. This completes a westward retrograde loop that began in early August. The planet will then resume its regular eastward orbital motion. The outer planet appears highest in the south once darkness falls, when it stands two-thirds of the way to the zenith. The magnitude 5.8 planet lies in southwestern Aries the Ram, near that constellation’s border with Pisces the Fish and Cetus the Whale. The closest guide star is magnitude 4.4 Xi1 (ξ1) Ceti, which lies 4 degrees to the southeast. A telescope reveals Uranus’ disk, which spans 3.6″ and shows a distinct blue-green hue.

Mercury reaches superior conjunction at 10am on Friday. This means the innermost planet lies on the opposite side of the Sun from Earth and remains hidden in our star’s glare. It will return to view in the evening sky late this month.

Mars grows more prominent before dawn with each passing week. The Red Planet now rises just after 4am and climbs 20 degrees above the southeastern horizon an hour before sunrise. Mars glows at magnitude 1.5 against the backdrop of constellation Scorpius the Scorpion, some 6 degrees north-northwest of its ancient rival, the 1st-magnitude star Antares in constellation Scorpius.

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

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

The 96% illuminated, waxing gibbous Moon rises at 2:43 p.m., Wednesday. Nightfall reveals the Moon inside the Winter Circle of the stars Rigel, Aldebaran, Capella, Pollux, Procyon, and Sirius. Betelgeuse, to the Moon’s lower right, in the constellation Orion, continues to fade in brightness. It is now estimated to be 1.5 magnitude, considerably dimmer than its brightness of 0.5 magnitude in October. Closer to the Moon, also to its lower right, is the star Zeta Tauri. This 3rd magnitude star, also known by the name Tianguan, meaning Celestial Gate, in Chinese, will be less than 1 degree from the Moon’s edge. Venus, shining at magnitude -4.0 dominates the west-southwestern sky until setting at 7:37 p.m. in Capricornus. Mars rises at 4:08 a.m. in Scorpius. Look for the -3.6 magnitude International Space Station to pass by Mars at 5:55 a.m., and Antares at 5:57 a.m., when Mars is 15 degrees above the southeastern horizon. The ISS will emerge from Earth’s shadow at 5:52 a.m. in the constellation Leo, and sail through Virgo before reaching Mars in Libra.

While the Moon is high over the western horizon, at about 3 a.m., Thursday, look about 1.5 degrees above it for M35, also known as the Shoe-buckle Cluster. M35 was discovered by Philippe Loys Cheseaux around 1745, and independently in 1750 by John Bevis. This open cluster of approximately 500 stars, the brightest of which are brighter than 13th magnitude and can be resolved by 10×50 binoculars, is as large as the Full Moon. The cluster has apparent magnitude of 5.3. Located at the foot of Gemini, M35 is 2,800 light-years away. M35 is the only Messier object in the constellation Gemini.

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

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

The Sun sets at 4:37 PM; night falls at 6:18. Dawn begins at 5:44 AM and ends with the Sun rising at 7:26.

The brilliant Moon dominates the night sky on both nights. Monday, the 84% illuminated Moon is found in Taurus, below the Pleiades star cluster; it is highest at 8:46 PM and sets at 4:04 AM, Tuesday. Tuesday’s Moon is highest 9:36 PM and situated about 3° above Taurus’ brightest star, Aldebaran; it sets at 5:14 AM, Wednesday.

Early evening features only one bright planet – Venus. The Clouded Planet blazes with minus 4th magnitude in Capricornus. This month, Venus experiences a dramatic increase in altitude. It also sets later from 2 ¾ to 3 ½ hours after sunset and enlarges from 13 to 15 arc-seconds, but shrinks in phase – from 82% to 74% lit. Venus sets at 7:28 PM.

Nightfall finds Neptune and Uranus in their normal positions. Neptune, in Aquarius, still glows with 8th magnitude, about 2 arc-seconds in size and sets at 9:37 PM. Uranus, in Aries, at 5th magnitude, 2 magnitudes brighter than Neptune, appears a bit larger in our instruments and sets 1:40 AM. Finder charts for both can be obtained from astronomy magazines and websites.

Mars is the only morning planet. The Red Planet rises in Libra at 4:12 AM, three hours before sunrise. By 5 AM it can be found about 5° above the star Graffias, one of the brightest stars in the Scorpion’s head.

By nightfall, Orion is already high in the southeastern sky. The bright white star Rigel marks the mighty hunter’s knee. A dim line of stars begins at Rigel and flows westward and downward until it disappears below the horizon. This is the river Eridanus. To see the full extent of this heavenly waterway, one must travel to Florida. There, Eridanus ends with the bright star Achernar, which literally means, “star at the river’s end.” The identity of this stream is a bit of a mystery. Ancient authors differ as to whether it refers to the Euphrates or the Nile. Both rivers were revered from time immemorial. Both were the sources of water and bountiful harvests. It is no coincidence that all the great civilizations and cities were founded along the banks of great rivers. The ancients thought of the Earth as sort of an island surrounded by a great body of water. The creation story in the Book of Genesis alludes to this view, as do Babylonian creation myths. The sky also bears out this vision. For the past several months we have observing water related constellations. Delphinus, the Dolphin, and Capricornus, the Sea Goat, began the procession, followed by Aquarius, Cetus and Pisces. Eridanus spills its heavenly waters to sustain this heavenly aquarium.