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Northern Sky

East Bay Moon Crescent/Photo by Stephan Hoglund

Deane Morrison is a science writer at the University of Minnesota. She authors the Minnesota Starwatch column, and contributes to WTIP bi-weekly on the Monday North Shore Morning program through "Northern Sky," where she shares what's happening with stars, planets and more.

 


What's On:
April Sky

Northern Sky: April 14 - 27, 2018

Northern Sky by Deane Morrison for  April 14-27 2018
 
If April can just let up on the rain and snow a bit, there are bright planets in both morning and evening for us to enjoy.
 
In the evening, we have Venus, the brightest of planets. It’s hard to miss—a real beacon in the west after sunset. But its beauty obscures a rather different reality. Venus has a thick atmosphere that’s mostly carbon dioxide. The planet owes its brightness to very reflective clouds of sulfuric acid droplets and crystals. Its surface atmospheric pressure is more than 90 times that of Earth’—as high as the pressure 3,000 feet down in the ocean. And its surface temperature hovers above 850 degrees Fahrenheit. In short, Venus is a hellish place with a heavenly face.
 
For an even more heavenly sight, have a look on Tuesday, April 17, when the moon pays a visit. On that evening Venus and a young fingernail crescent moon will make a lovely pair.
 
If you go outside on or before the 17th, before the moon gets bright enough to interfere, try comparing Venus to Sirius, the brightest of stars, which will be rather low in the southwest. Spoiler alert: It's no contest; Venus easily outshines Sirius.
 
Sirius and the other winter stars are busy exiting the sky to the west. In their place is the spring constellation Leo the lion. It’s now high in the south during prime evening viewing hours. Look for a backward question mark of stars with a bright one--namely, Regulus--at the base. That question mark is known as the Sickle, and its stars represent Leo's head and heart. The hindquarters and tail are a triangle of stars just east of the Sickle.
 
In the morning sky, the best thing to see is Mars because it's getting really bright now as Earth gets closer and closer. It appears as a red dot low in the southeast for a couple of hours before dawn. West of Mars is Saturn, and even farther west is brilliant Jupiter.
 
In astronomy news, a University of Minnesota researcher--formerly at UC Berkeley--led a team that found the most distant individual star ever observed. Its light took nine billion years to reach Earth--or, more exactly, the Hubble Space Telescope. It's a large blue star, but it could never have been seen from, as NASA puts it, more than halfway across the universe if nature hadn't given us a cosmic magnifying glass. That magnifying glass is a cluster of galaxies that are between us and the star, which the team named Icarus.
 
It works like this. Massive objects like stars, galaxies, and clusters of galaxies act like lenses. Their gravity is so strong, it bends the space all around them, and light bends with it. Icarus is behind that cluster of galaxies, but when light from the star got near the cluster, it was bent by the cluster's gravity and curved around the cluster, then continued on toward us. The bending focused and magnified Icarus’s light by about 600 times. But that wasn't enough; the researchers hypothesize that Icarus only became visible—briefly—when a sun-sized star in the cluster of galaxies moved in front of Icarus. Then, that star took the light from Icarus-- already magnified 600 times--and focused it again, resulting in a total magnification of 2,000 times. Enough for Hubble to pick up. This work gives astronomers a way to study stars in very distant galaxies. We see them as they existed billions of years ago, when the universe was much younger.
 
The team named the star Icarus because it had a brief, you might say, moment in the sun, just like its namesake from Greek mythology. He made wings of feathers, held together with wax, but he flew too near the sun. The wax melted, and that was it for Icarus.  
 

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April 2nd Sky

Northern Sky: March 31 - April 13, 2018

Northern Sky - by Deane Morrison for March 31 - April 13, 2018.

Deane Morrison is a science writer at the University of Minnesota.
She authors the Minnesota Starwatch column.  It can be found on the University of Minnesota website at 
astro.umn.edu.

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Predawn Sky SSW April 2 2018

Northern Sky: Mar 17 - 30

Northern Sky by Deane Morrison -  March 17-30 2018

March came in with a full moon, and it's going out with a full moon. Meanwhile, there's plenty going on in both the morning and evening skies.
 
Look to the south an hour before dawn and you'll see Jupiter blazing away. Then look eastward to see the stars of Scorpius, especially bright red Antares, the heart of the scorpion. Moving east again, we have the Teapot of Sagittarius. Right above the Teapot, Saturn seems to float motionless from day to day. But Mars is moving eastward against the background of stars, and it's rapidly closing in on Saturn. Mars stays to the west of Saturn until the end of March, but in the first week of April it's going to zip right below the ringed planet.
 
If you look above and east of Saturn and Mars, you'll see the Summer Triangle of bright stars high in the southeast. And off to the west of Jupiter, and higher, we have Arcturus, the brightest star in the northern hemisphere of sky. If you're ever in doubt as to which star is Arcturus, you can find it by extending the curve of the Big Dipper's handle.
 
In the evening sky, Venus is low in the west after sunset. So is Mercury, but not for long. The best night to see it was March 15. But now it's fading and dropping toward the sun because it's on its way between Earth and the sun. On the 17th Mercury is to the upper right of Venus, which is by far the brighter planet. On the 18th, a young crescent moon appears with the two planets--that will be lovely. But by the 21st Mercury will have dropped down to the level of Venus, and then it just plummets out of sight.
 
Sirius, the brightest star in the night sky, is still up. It's somewhat low in the south to southwest after nightfall. If you've never seen it, do take a look. And while you're at it, grab some binoculars and look for the Beehive star cluster, an inconspicuous little jewel that is now high in the south.
 
The Beehive is between two bright stars. One star is Pollux, the brighter of the Gemini twins. To find it, start with Sirius and look up to the bright star Procyon, and then up about the same distance again. The other star is Regulus, the brightest in Leo, the lion. It's east and a little south of Pollux. The Beehive is a bit dim, so you may need a star chart to get its exact location. But seeing it through binoculars is a real treat.
 
The spring equinox arrives at 11:15 a.m. on Tuesday, March 20. At that instant, Earth will be lighted from pole to pole and it won't be tilted with respect to the sun. That's because our spring equinox is an inflection point, the point at which the Earth’s orientation to the sun switches so that the Northern Hemisphere starts tilting toward the sun. The tilt changes fastest in the days closest to the equinoxes; therefore, these days we're gaining daylight at the maximum rate, approximately three minutes a day. Also, starting at the spring equinox, days get longer as you travel north.
 
March gets its second full moon on the 31st. This qualifies as another blue moon. The moment of fullness comes at 7:37 a.m. However, the moon sets over Grand Marais at 7:10 that morning. If you want to see the moon at its fullest, you might want to get outside by 6:30, or even earlier if there are obstructions to your view of the western horizon. Or just enjoy it the evening of the 30th.
 

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March 1 Sky.jpg

Northern Sky: March 3-16, 2018

Northern Sky -  March 3-16 2018

During the first half of March, the moon wanes away to the thinnest of crescents and then to a new moon on the morning of the 17th. In the process, the moon moves across the morning sky and gives us more moon-free time to enjoy the evening sky. 
 
These days we can see Venus and Mercury together above the sunset horizon. Mercury is the closest planet to the sun, and so it never appears very far from the sun, and the sun’s glare often makes it hard to catch Mercury. To see Mercury and Venus, look low in the west shortly after sunset—maybe 30 minutes after. Venus is by far the brighter planet, so it's easy to tell the two apart. Mercury climbs up and passes closest to Venus on the 3rd, when the planets will be about two moon widths apart. Mercury gets higher until the 15th, when it will be at its greatest angular distance from the sun, and then it rapidly falls into the sunset. Whenever Mercury or Venus falls into a setting sun, that's the beginning of the planet’s next trip between Earth and the sun. When it emerges from that trip it reappears in the morning sky.
 
Mercury was, of course, the messenger of the gods. And it's easy to see how it got that name. From our point of view, it's always racing back and forth between the evening and morning sky, never sticking around for very long. As for Venus, right now it’s also climbing in the evening twilight, but slowly, and it will stick around for several more months.
 
If you're out after the sky gets good and dark, enjoy the bright winter stars in the south and southwest. Next month they'll begin setting in the early evening.
 
In the morning sky, the predawn sky, we have the three outer planets that are visible to the naked eye lined up in the southeast and south. From left to right they are Saturn, Mars and Jupiter. Between Mars and Jupiter is Antares, a gigantic red star that marks the heart of Scorpius. But the real star of the show is Mars. If you can get out and watch every day, or every other day, you can see it moving eastward against the background of stars, away from Antares and Jupiter, and toward Saturn.
 
Starting on the 7th, that waning moon I mentioned comes in handy for telling all these objects apart. As it wanes, the moon sweeps from east to west across the morning sky. On the 7th, the moon is close to Jupiter. On the 8th, it appears above Antares. On the 9th, it's approaching Mars, and on the 10th, it's passed Mars and sits between Mars and Saturn. And on the 11th it has passed Saturn and appears near the bowl of the Teaspoon, which is a curved line of stars above the handle of the Teapot of Sagittarius. Over the next few mornings, the moon will be thinner and closer to the sun, and that may make it an even nicer companion to the planets and stars.
 
The Summer Triangle of bright stars is also up, high in the east, before dawn. And high in the south to southwest is Arcturus, the brightest star in Bootes, the herdsman, a lovely kite-shaped constellation.
 
With the moon mostly absent from the early evening sky, we have another chance to find the elusive zodiacal light an hour or so after sunset. It appears as a faint finger of light pointing up along the sun's path. The zodiacal light is the result of sunlight reflecting off dust in the plane of the solar system.
 
 

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Feb Sky.jpg

Northern Sky: Feb 17 - Mar 2 2018

“Northern Sky” by Deane Morrison  Feb. 17-March 2 2018

In the second half of February, Venus starts to peek out from the sun's afterglow and slowly climb into the evening sky. On Saturday, February 17, there's a thin young crescent moon in the west-southwest, and if you look half an hour after sunset you may spot Venus way below and a little to the right of the moon. In the coming days, the moon will move on to the east, but keep looking in the same spot for Venus, although it will be a little higher each night.
 
As the moon makes its way eastward, it waxes. Between the evenings of the 22nd and 23rd, it passes the bright star Aldebaran, the eye of Taurus, the bull. The evening of the 24th, it travels the night sky above Orion.
 
The moon finally becomes full on Thursday, March 1st, at 6:51 p.m. It'll be big and bright because it'll be just a couple of days past its closest approach to Earth in this lunar cycle. And, since moonrise over Grand Marais comes at 5:32 p.m.--barely more than an hour before perfect fullness--it'll be one of the roundest moons. Also, this gorgeous moon rises against a pale sky opposite a setting sun. It crosses the night sky below the belly of Leo, the lion, a spring constellation.
 
The latter half of February is a good time to watch the predawn show because there’s little interference from the moon. Three planets are all well up by an hour before sunrise, and they form an almost perfectly straight line. Starting low in the southeast and moving diagonally up and to the right, they are Saturn, Mars and Jupiter. Off to the right of Mars is Antares, the bright heart of Scorpius. Antares' name means rival of Mars, and as Mars brightens over the coming months it'll really outshine Antares and even begin to rival Jupiter.
 
Unlike Mars, Jupiter and Saturn don't change much in brightness because they're always very far from Earth no matter where Earth is in its orbit. Therefore, their distance from us can only change by a relatively small amount. But the orbits of Mars and Earth are much closer, and like runners in adjacent lanes on a track, our two planets vary widely in relative distance. As Earth gains on Mars and gets ready to lap it in the race around the sun, we get a lot closer. Mars’s mid-February distance is about 143 million miles; that shrinks to only 36 million miles when we lap it in July.
 
Mars also differs from Saturn and Jupiter in another way that we don’t need a telescope to see. If you watch the planets’ positions with respect to the stars, it looks as though Saturn and Jupiter are barely budging. And why not? Earth’s orbital motion pushes both stars and planets westward. But Mars is budging quite a bit compared to the background of stars, because its orbital motion, eastward, is so much faster than the other outer planets'. Sure, Earth’s motion also pushes Mars westward, but not nearly as fast as it does the background stars, or Jupiter or Saturn. From morning to morning you can watch Mars plowing its way eastward, away from Jupiter and Antares and toward Saturn. In the first week of April, Mars passes Saturn.
 
Also in the predawn sky, the Big Dipper is now hanging high in the west. If you follow the curve of its handle, that brings you to Arcturus, whose name means follower or guardian of the bear. Arcturus is a brilliant star, high to the upper right of Jupiter. Also try finding the crown of Scorpius, which is three stars that now look like a shield protecting Antares from Jupiter.
 

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NSky-February 2018.jpg

Northern Sky: Feb 3 - 16, 2018

Northern Sky  by  Deane Morrison 
Feb. 3-16 2018
 
As we approach the middle of February, the moon spends more and more time in the morning sky, and that's good for everybody who would rather see stars in the evening.
 
This is the best time of year to enjoy all the bright winter constellations I've been talking about. If you go out an hour after sunset, you'll see them in the southeast to south. Sirius is the brightest star of all, and it's also the lowest of the bright winter stars. Sirius is called the Dog Star because it dominates Canis Major, the larger of Orion's hunting dogs. In ancient times, people thought that during the summer, when Sirius appears nearer the sun in the sky, its heat combined with the sun's heat to produce the hottest days of the year, which were dubbed the dog days. Of course, Sirius has nothing to do with it, but when looking at it against a dark winter sky, it's easy to see how people could think that.
 
Sirius is also part of two well-known geometric arrangements of stars. One is the Winter Triangle. Besides Sirius, the stars in the triangle are Procyon, which is above and a little east of Sirius, and reddish Betelgeuse, which is a little west of Procyon. Then there's the Winter Hexagon. Again starting with Sirius, move around clockwise to Procyon, which is in Canis Minor, the little dog; then Pollux, the brighter Gemini twin; Capella, in Bootes the herdsman--this is the highest star in the hexagon; then Aldebaran, the eye of Taurus, the bull; and finally Rigel, in Orion.
 
In the morning sky, the planet show continues. The planets and neighboring stars are moving out of the southeast and into the south now. All three morning planets are rather low, but the highest, brightest and most western one is Jupiter. Moving to the left, or east, the constellation Scorpius has Mars, and below Mars is the gigantic red star Antares, the heart of the scorpion. The bright light to the lower left of Mars and Antares is Saturn. At this point, Mars isn’t especially bright, because it’s about 143 million miles away. But when Earth catches up to it this summer, it’ll be almost four times closer—just 36 million miles away. And pretty darn bright.
 
The moon wanes away to the new phase on February 15th, and on its way it visits the morning planets. Between the 7th and 8th it sweeps by Jupiter. Between the 8th and 9th, it passes Mars. On the 9th, the moon, Mars and Antares will make a nice trio of objects. On the 11th, the moon will be right above Saturn, and Saturn will be right above the lid of the Teapot of Sagittarius. On the 12th, the crescent moon will be sitting in the curved line of stars known as the Teaspoon, which hangs above the handle of the Teapot. On the 13th, the moon will be a lovely thin crescent. On the 16th, a young moon of the next cycle appears in the west, in the sun's afterglow. You'll have to look about half an hour after sunset to see it, and you may catch Venus to the lower right of the moon. This month, Venus is just starting a climb into the evening sky.
 
Also in the evening, look for the pale and elusive zodiacal light in the west as soon as the sky gets dark. The zodiacal light appears as a broad finger, or cone, of light extending up along the sun's path. It's caused by sunlight reflecting off dust in the plane of the solar system. You need dark skies to see it, and if you do, count yourself among the fortunate few.
https://ssl.gstatic.com/ui/v1/icons/mail/images/cleardot.gif
 

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Supermoon by Alex Galicia

Northern Sky: Jan 20 - Feb 2, 2018

Northern Sky by Deane Morrison  for January 20 through February 2, 2018.

Deane Morrison is a science writer at the University of Minnesota.
 She authors the Minnesota Starwatch column, and in this feature
she shares what there is to see in the night sky in our region.

Deane Morrison’s column “Minnesota Starwatch” can be found on the
University of Minnesota website at     astro.umn.edu.

 

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Northern Sky January 6-19

Northern Sky - Early January 2018  by Deane Morrison

Deane Morrison is a science writer at the University of Minnesota.
 
She authors the "Minnesota Starwatch" column, and in this feature
she shares what there is to see in the night sky in our region.
 
Her column “Minnesota Starwatch” can be found on the University
of Minnesota website at  astro.umn.edu. 
 

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SuperMoon.jpg

Northern Sky: Dec 23 - Jan 5

Northern Sky - December 23 to January 5 - by Deane Morrison.

Deane Morrison is a science writer at the University of Minnesota.
 
She authors the Minnesota Starwatch column, and in this feature
she shares what there is to see in the night sky in our region.

Her column “Minnesota Starwatch” can be
found on the University of Minnesota website at
 astro.umn.edu 
 

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