Minnesota Starwatch 2020

Minnesota Starwatch by Deanne Morrison, designed to inform the broadest possible community of the appearance of the nightly sky and current activities in newspapers, continues to be published in several newspapers throughout the state.

Contact:
Deane Morrison
University Relations
(612) 624-2346
morri029@umn.edu

OCTOBER 2020

Minnesota Starwatch: Mars and the Moon, as seen looking east at nightfall on October 2nd.

October begins and ends with a full moon.

The first rises the evening of the 1st, only about three hours past the exact moment of fullness. Following it into the eastern sky is Mars, now too bright to be washed out by any lunar luster. Over to the south, brilliant Jupiter and dimmer Saturn are drawing nearer, en route to a close encounter in December.

The night of the 2nd, Mars and the waning moon rise and travel the night sky together. On the 13th, Earth laps Mars in the orbital race, passing a mere 38.6 million miles from the red planet. That night Mars shines down from the constellation Pisces, where no bright stars will be close enough to rival its splendor.

Above and slightly west of Mars, the Great Square of Pegasus is now in prime viewing position. Look below it on a moonless night and see if you can find the ringlike Circlet of Pisces, representing one of two fishes in the constellation.

In the predawn sky, Venus dazzles in the east. Watch the bright star Regulus, in Leo, the lion, glide by the planet early in the month, passing closest on the 2nd and 3rd. On the 13th and 14th, waning crescent moons join Venus. All month long, look off to the west of Venus to see brilliant Sirius shining from its berth in Canis Major, the big dog. This year October and November give us a great chance to compare Venus, the brightest planet, with Sirius, the brightest star in the night sky. But it will be easier this month because the two will be closer.

October’s second full moon shines the night of the 30th–31st. The second full moon in a month is often called a blue moon, but the original definition was the third of four full moons occurring in a single season. By that definition, we’ll see our next blue moon on August 22, 2021.

October bids farewell with Halloween, an astronomically based holiday. To the ancient Celts it was known as Samhain, one of four cross-quarter days falling midway between an equinox and a solstice. It began at sundown on October 31st, when all the evil spirits that had been cooped up since May Day were released to wreak havoc on humankind. People lit lanterns in gourds to ward them off and left food offerings to appease them—traditions that survive in jack o’ lanterns and trick-or-treating.

SEPTEMBER 2020

Minnesota Starwatch: the Beehive Star Cluster, Venus, and the waning Moon, as seen facing east 90 minutes before sunrise on September 14th.

September gets right down to business with a full moon the night of the 1st. It makes a solo journey across the night sky, there being no bright stars close to it. Only lonely Fomalhaut, the mouth of Piscis Austrinus, the southern fish, will glimmer below the bright lunar disk.

But the full moon will be about midway between bright planets. Off to the west, brilliant Jupiter and dimmer Saturn are high in the south at nightfall. Off to the east, Mars climbs over the horizon a couple of hours before midnight, its ruby orb waxing to rival Jupiter as Earth catches up to it in the orbital race.

The night of the 5th, a waning moon rises close to Mars. The moon will be reddened like a rising sun—or the planet that appears ready to ride the moon across the night sky. By the predawn hour, however, the moon and Mars will have shifted positions, with the moon now higher than the red planet.

The evening sky will be moon-free for about two weeks in the middle of September. Get out your star chart and look for the fall “water” constellations Capricornus, the sea goat; Pisces, the fishes; and Aquarius, the water bearer. Or even dim Piscis Austrinus. And watch the Great Square of Pegasus make its grand entrance in the east.

In the predawn sky, a last quarter moon shines high on the 10th. Look to the east on the 14th, when a crescent moon appears close to luminous Venus and the dim but lovely Beehive star cluster.

Fall arrives with the autumnal equinox at 8:31 a.m. on the 22nd. At that moment the sun crosses the equator into the southern sky and an observer in space would see Earth lighted from pole to pole. Also, from then until spring, the days shorten as we go farther north.

AUGUST 2020

Minnesota Starwatch: Saturn, Jupiter, and the waning Moon, as seen facing south at nightfall on August 1st.

Summer may fade in August, but that brings darker skies and longer hours to watch stars and planets.

The month starts out with a nearly full moon rising the evening of the 2nd. That night it follows Saturn and brilliant Jupiter across the sky, becoming full at 10:59 a.m. on the 3rd. However, by that time the moon will have set. To see it at its roundest, check your local time of moonset and go outside early enough to catch it before it sinks in the southwest.

The waning moon proceeds to sail through the fall constellations Capricornus and Aquarius. On the night of the 6th-7th it appears below the ring-shaped Circlet of Pisces, a somewhat dim figure below the brighter Great Square of Pegasus. On the 8th-9th, a still hefty moon travels the night sky with Mars.

With Earth closing in on it in the orbital race, Mars looks much bigger and brighter than usual. It’s up in the east by midnight and, surrounded by only dim stars, unmistakable. In the predawn sky, Mars is high in the southeast to south while Venus, also unmistakable, blazes away low in the east. On the 15th Venus and a crescent moon appear next to the feet of the Gemini twin Castor.

The Perseid meteor shower is predicted to peak between late night and dawn on the 11th-12th, but the nights before and after could also be good. Typically fast and bright, Perseids stream from the northeast, and many leave persistent trails. A bright waning moon may interfere, though, depending on which day and time you go out.

When no meddlesome moon is up at nightfall, don’t miss the smorgasbord of stars. High in the west, brilliant Arcturus anchors kite-shaped Bootes, the herdsman. Immediately east hangs the semicircular Corona Borealis, or northern crown; its jewel is called Gemma or Alphecca. Next comes the hourglass of stars on the torso of upside-down Hercules.

Beside Hercules shines Vega, the peer of Arcturus and beacon of Lyra, the lyre. Below Vega, a small parallelogram of stars outlines the lyre. Moving east again, somewhat dimmer Deneb marks the tail of Cygnus, the swan, and the head of the Northern Cross. To the south, Altair, in Aquila, the eagle, forms the sharp point in the Summer Triangle of stars, which includes Vega and Deneb. And slightly above and east of Altair, diminutive Delphinus, the dolphin, leaps into a dark sea.

JULY 2020

Minnesota Starwatch: Pleiades, Aldebaran, Venus, and the Moon, as seen when facing East before dawn on July 17.

This month Jupiter and Saturn dominate the evening sky, while Venus climbs into prominence as a predawn planet.

Venus comes out higher in the east every day, freeing itself from the sun’s foreglow. On the 3rd, our brilliant sister planet begins a 10-day glide across the face of Taurus, the bull, represented by the V-shaped Hyades star cluster. On the 12th, Venus passes just one degree, or two moon widths, from Aldebaran, the eye of the bull, which is not part of the Hyades. Hanging above the action is another star cluster: the Pleiades. Venus crossed the Pleiades in April, before plummeting out of the evening sky. Don’t miss the show on the 17th, when a waning crescent moon joins Venus and Aldebaran.

Jupiter and Saturn are low in the southeast at nightfall. Much brighter Jupiter and the ringed planet both reach opposition this month, when Earth laps them in the orbital race and they appear opposite the sun in the sky. Jupiter’s opposition comes on the 14th, Saturn’s on the 20th. Both planets now trace low arcs across the sky each night because in summer, our hemisphere is tilted toward the sun and thus away from any planet opposite, or nearly opposite, the sun.

But Mars will be fairly high at its October opposition because by then we will tilt more toward the night sky than toward the sun. As its opposition date approaches, Mars brightens daily, but it’s still a morning planet. By month’s end, though, it just manages to scrape over the eastern horizon by midnight.

July’s full moon arrives shortly before midnight on the 4th. Between 10:07 p.m. and 12:52 a.m. that night, the moon’s uppermost part undergoes a penumbral eclipse, where Earth blocks some sunlight from reaching the moon. This eclipse will be so slight that only the sharpest eyes will notice it.

Also on July 4, Earth reaches aphelion, its farthest point from the sun. At that moment we’ll be 94.5 million miles from our parent star and traveling most slowly in our orbit. Because Earth reaches its minimum speed in the northern summer, it takes longer to get through this part of our orbit. As a result, in the Northern Hemisphere, spring and summer together last a few days longer than fall and winter. In the Southern Hemisphere, it’s the opposite; spring and summer there are shorter than fall and winter.

JUNE 2020

Minnesota Starwatch: Arcturus, Spica, and the waxing Moon, Facing south at nightfall on June 28th.

Venus has just left the evening sky, and now Jupiter and Saturn are moving in. By mid-month both will be up in the southeast before midnight. Jupiter, by far the brighter planet, shines west of Saturn and leads the ringed planet across the night sky.

Mars doesn’t quite make it into the evening sky. But it rises earlier each day, approaching midnight from the morning side. By dawn Mars will be a fairly bright dot in the southeast. As for Venus, it reappears in the morning sky this month, but doesn’t climb out of the sun’s foreglow until late June or early July.

If you’re out at nightfall, the brilliant star Arcturus dominates the southern sky. Arcturus, the jewel of kite-shaped Bootes, the herdsman, is the brightest star in the northern hemisphere of sky. However, it’s barely brighter than Vega—the beacon to the east of Arcturus—so they can be considered co-holders of that title.

Between the 28th and 29th, a waxing moon glides between Arcturus and Spica, the brightest star in Virgo, the maiden, which shines about 30 degrees below Arcturus. Whenever Spica is up, you can find it by following the curve of the Big Dipper's handle —always somewhere to the north—to locate Arcturus, then keeping going to find Spica. In other words, “arc to Arcturus, speed on to Spica.”

June’s full moon arrives at 2:12 p.m. on the 5th. It follows Scorpius and Antares, the scorpion’s bright red heart, across the night sky. Jupiter and Saturn follow the moon that night; between Jupiter and the moon is the Teapot of Sagittarius.

If you like challenges, look for a very old crescent moon to the lower left of Venus, right above the east-northeastern horizon about half an hour before sunrise on June 19. Then look for an extremely young and thin crescent moon getting ready to set over the western horizon at nightfall on the 23rd. Use binoculars, and see if you can find the Beehive star cluster right below the moon.

Summer begins with the solstice, at 4:44 p.m. on the 20th. At that moment the sun reaches a point over theTropic of Cancer, and an observer from space would see Earth lighted from the Antarctic Circle up to the North Pole and beyond to the Arctic Circle on the night side of the planet.

MAY 2020

Minnesota Starwatch: Mars, Saturn, Jupiter, and the waning Moon, as seen facing south at predawn on May 15th.

In May we lose the two brightest lights in the evening sky: Venus and Sirius, the brightest of stars.

Sirius begins the month very low in the southwest and drops out of sight by mid-month. In the last two weeks of May, most of the other bright winter stars also disappear. Venus, a brilliant evening star, plummets through the sky and is gone by month’s end. Near the end of its fall, Mercury pops into the sky; it passes Venus on the 21st, when both are extremely low and in the sun’s afterglow. Venus reappears in the morning sky in July, but then only the early—very early—birds will catch a glimpse of it.

At nightfall Leo, the lion, appears to be leaping downward in the southwest. Look for the bright star Regulus, at the base of a backward question mark of stars called the Sickle; this is the lion’s head. East of Regulus, fairly bright Spica shines from its berth in Virgo, the maiden. Above Spica, radiant Arcturus anchors kite-shaped Bootes, the herdsman.

Jupiter and Saturn rise a couple of hours after midnight on the 1st, appearing earlier every morning. Mars follows them by about two hours. All three planets are well up in the southeast before day starts to break.

As the month goes by, Mars climbs steeply but makes little progress westward. Saturn and brilliant Jupiter, however, hurry westward while making only modest gains in altitude. These giant planets are gradually approaching each other, even as they glide steadily farther from Mars. Above Saturn and Jupiter shines the Summer Triangle of bright stars. Altair, in Aquila, the eagle, is the closest to the planets.

May’s full moon will be another big, bright supermoon. Fullness happens at 5:45 a.m. on Thursday, the 7th. If you watch it rise the night before or after, it will be close to half a day before or past full. If you go out the morning of the 7th, remember to check your local time of moonset. Moonset times range from 5:59 a.m. in Grand Marais to 6:32 a.m. in Pipestone.

APRIL 2020

Minnesota Starwatch: Pleiades and Venus, looking west after nightfall on April 2.

April opens with spectacular views of planets in both the morning and evening skies. Early risers who look to the southeast will see Jupiter, brilliant in the predawn darkness. Off to the east of Jupiter, red Mars hangs right below golden Saturn.

But this closeness doesn’t last. The very next day, it will be obvious that Saturn has moved away from Mars. In fact, both Saturn and Jupiter are heading westward, away from the red planet. On the 9th, Saturn will be almost exactly midway between Mars, to the left, and Jupiter. By month’s end, the gap between Mars and Saturn will have opened to nearly 20 degrees.

While Saturn and Jupiter are pulling away from Mars, Earth is moving closer. During April the distance to Mars drops from 135 million miles to 114 million miles. Also, Jupiter is slowly drifting closer to Saturn. In December these two planets make a very close pass.

In the evening sky, Venus visits the lovely Pleiades star cluster. On the 1st, the cluster hovers close above the queen of planets. The next night, Venus has arrived at the border, and on the 3rd the planet appears to be another star in the cluster. On the 4th, Venus is above the Pleiades, and from then on the two objects rapidly separate. The one wrinkle is the bright waxing moon that shines those nights, so keep your binoculars handy.

And if that weren’t enough, April’s full moon is one of the closer ones this year and qualifies as a “supermoon.” It rises the evening of the 7th, looking not only bigger and brighter than usual, but very round because it’ll be only a couple of hours or so from the moment of perfect fullness. Also, have a look on the 25th, when a young crescent moon of the next cycle appears below Venus and next to Aldebaran, the eye of Taurus, the bull.

April ends with an astronomically based holiday that the ancient Celts (and many contemporary ones) called Beltane. It was celebrated on May 1, which began formally at sundown April 30 and was one of four “cross-quarter” days falling midway between an equinox and a solstice. The night of April 30 was when evil spirits that had been wreaking havoc since Halloween—another cross-quarter day—had a last fling. At dawn on May 1, they had to begin their annual six-month exile from the world of humans. Beltane was, and is, a celebration of the coming summer and hopes for an abundant harvest.

MARCH 2020

Minnesota Starwatch: Jupiter, Saturn, and Mars, low in the southeast, 90 minutes before sunrise on March 20.

In March, the action in the predawn sky really picks up. The month opens with Mars, Jupiter and Saturn forming a straight line, in that order from right to left, above the southeastern horizon. On the 4th, the three planets are spaced almost evenly apart.

But that neat arrangement soon gives way as the planets switch positions. Jupiter and Saturn are about to leapfrog past Mars, and all because Mars, being the closest to the sun, orbits the fastest.

What’s happening is that Earth’s orbit is carrying us eastward and thus toward all these planets, making them move higher and westward. But Mars’s own orbit carries it much more rapidly eastward against the background of stars than the orbits of Jupiter and Saturn carry those planets.

As a result, Mars resists the westward movement imposed by Earth’s orbit and appears to sail eastward toward—and past—the two giant planets. Actually, though, Mars is mostly holding its own as Jupiter and Saturn sail past it on their westward journey.

Have a look on the 18th, when Jupiter and Mars make a close pair while a crescent moon hangs right below them. The next morning, Jupiter and Mars will be closer yet and the moon will now appear below Saturn. On the 20th, Jupiter passes a mere 0.7 degrees—slightly more than a moon width—above Mars. On the 31st, the ringed planet passes about a degree above the red planet. In April the new lineup will be, from right to left, Jupiter, Saturn and Mars, with the gap between Mars and the other two planets rapidly widening.

In the evening sky, a young moon comes out below Venus on the 26th and 27th. And don’t miss the show as the brilliant planet and the Pleiades star cluster approach each other in the last week of March. Mark your calendars for April 2nd and 3rd, when Venus glides, spectacularly, in front of the Pleiades. Be sure to have binoculars handy.

March’s full moon shines the night of the 9th. It will be big and bright, though more than six hours past full when it rises that evening.

Spring arrives with the vernal equinox at 10:50 p.m. on the 19th. At that moment the sun crosses the equator into the northern sky and Earth will be lighted from pole to pole.

FEBRUARY 2020

Minnesota Starwatch: the Moon, Taurus, and Pleiades, looking southeast at nightfall on February 2nd.

A dazzling evening “star,” Venus comes out in twilight and sticks around long enough to outshine all the real stars against a dark sky. So bright is our sister planet, it has been mistaken for a UFO. Watch it climb in the southwest throughout the month, and be sure to catch it on the 26th and 27th, when a waxing crescent moon appears near it.

The moon takes many partners this month, especially as it tours the group of bright winter constellations now moving onto center stage in the southern sky. On the 3rd, a bright moon crowds the face of Taurus, the bull, and its bright star Aldebaran, the bull’s eye. On the 6th, a fatter moon will shine near the Gemini twins Pollux (the brighter) and Castor.

February’s full moon rises in the late afternoon of the 8th and reaches fullness at 1:33 a.m. on the 9th. This full moon will be quite big and bright, since the moon reaches perigee, its closest approach to Earth in an orbit, only about a day and a half later.

In the morning sky, the three outer planets—Mars, Jupiter and Saturn—are positioning themselves for a spectacular dance in March and early April. All rise in the southeastern predawn sky; Mars first, then Jupiter and finally Saturn, which may be too low to easily see until the last few days of the month. When the three planets are all above the horizon, they will form a nearly straight line, with brilliant Jupiter in the middle.

On the 18th, a thick waning moon passes in front of Mars, making the red planet disappear behind the moon’s illuminated side. Mars may be hard to see next to the moon’s glare, and the time of Mars's disappearance varies slightly by location. But if you get out by 5:45 a.m. you should be able to watch the event. 

On the 2nd, we celebrate an astronomically based Celtic holiday known as Imbolc, or lamb’s milk. It was one of four cross-quarter days falling midway between a solstice and an equinox. It was held that a sunny day predicted cold and continued winter, but a heavily clouded, shadow-free day portended warm spring rains that would soften up the fields for planting. This myth survives in modern Groundhog Day rituals; if the groundhog sees its shadow it means six more weeks of winter, whereas thick clouds mean spring is right around the corner.

JANUARY 2020

Minnesota Starwatch: the Moon, Mars, and Scorpius, looking southeast 75 minutes before sunrise on on January 20.

Set against the cold morning sky, the warm red of Mars and its stellar counterpart Antares lends a note of cheer to the January darkness. Mars begins the year as a glimmering red dot somewhat low in the southeast, above Antares, the heart of Scorpius. Day by day, the stars of Scorpius approach and sweep past Mars. Between the 6th and 9th, the three stars known as the Crown of Scorpius sail by the red planet. Earth’s orbital motion is pushing both Mars and the stars of Scorpius westward, but the stars outstrip Mars because the planet, moving eastward in its own orbit, is able to slow its drift.

Before Scorpius gets too far west, we have a good chance to compare Mars to gigantic Antares, the red star whose name means rival, or antagonist, of Mars. The star and planet come closest on the 18th, when they’ll be 4.8 degrees apart, with Antares to the lower right of Mars. Mars and its rival are now of comparable brightness, but Mars is slowly cranking up the wattage. A waning crescent moon hangs above the pair on the 20th. Jupiter breaks into the southeastern morning sky late in the month. Saturn follows, but won't be easily visible until February. Both planets will rendezvous with Mars before winter is over.

In the west, Venus dominates the early evening sky. As the month goes by, Venus climbs toward the slightly dim, ring-shaped Circlet of Pisces. Above the Circlet, the Great Square of Pegasus is now tipped as it heads into the sunset, along with the Circlet and other autumn stars. On the 27th and 28th, a waxing crescent moon appears with Venus.

January’s full moon arrives at 1:21 p.m. on the 10th, just a few hours before rising for the night. It travels the night sky near the Gemini twins Pollux (the brighter) and Castor.

Earth reaches perihelion, its closest approach to the sun in an orbit, on the 5th. At that point we’ll be 91.4 million miles from our parent star. We in the Northern Hemisphere can feel lucky that perihelion happens during winter, because the nearer the Earth is to the sun, the faster it moves along in its orbit. That means it moves through the fall and winter part of its orbit faster than it moves through the spring and summer part. As a result, the Northern Hemisphere gets about five more days of spring and summer than does the Southern Hemisphere.