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North Shore Morning Monday

AM Community Calendar/photo by masochismtango on Flickr

  • Monday 8-10am
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News & Information

News and information, interviews, weather, upcoming events, music, school news, and many special features. North Shore Morning includes our popular trivia question - Pop Quiz! The North Shore Morning program is the place to connect with the people, culture and events of our region!

 


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Northern Sky: Sept 15 - 28

Norther Sky – by Deane Morrison  -  Sept. 15-28 2018

During the last two weeks of September, we have bright planets in the evening and a couple of regularly scheduled astronomical events.
 
If you face south 40 to 45 minutes after sunset, you’ll see Mars fairly low and still quite bright. Turning a bit westward, you’ll see the Teapot of Sagittarius, with Saturn above it. Next, even lower than Mars, there’s Antares, the red heart of Scorpius. Finally, low in the southwest, we have Jupiter. You probably won’t see Venus, though, especially later in the month, because it’s dropping into the sunset on its next trip between Earth and the sun. That trip also takes it, officially, from the evening to the morning sky.
 
As for stars, the Summer Triangle of bright stars is high in the south after nightfall. And in the west, the brilliant star Arcturus is still pulling its kite-shaped constellation, Bootes the herdsman, down toward the horizon. You might want to compare Arcturus with Vega, the brightest star in the Triangle and see if you can tell that Arcturus is ever so slightly brighter.
 
Now, about those scheduled events. First is the fall equinox. It arrives at 8:54 p.m. on Saturday the 22nd. At that point an observer from space would see the sun poised over the equator and Earth lighted from pole to pole. The equinox is also a crossover time of sorts. In spring and summer, the Northern Hemisphere tilts toward the sun, and the farther north you go, the longer the day length. But after the fall equinox, it tilts away from the sun and the days get shorter as you go north.
 
And, this is the time of year when the Northern Hemisphere is most rapidly shifting its tilt away from the sun. Which brings us to the second scheduled event: the harvest moon. Some say the harvest moon is the full moon closest to the fall equinox, others say it’s the first full moon after the equinox. This one qualifies on both counts. The full harvest moon, on Monday, September 24, rises over Grand Marais at 7:12 p.m., which is just two hours and 40 minutes before perfect fullness, so it’ll be nice and round.
 
But the harvest moon is more than just a name. Here’s how it goes. The full moon occupies a position on the other side of Earth from the sun—so it’s opposite the sun in the sky. Therefore, when we’re tilting most rapidly away from the sun, making it move south and rise later each day, we’re tilting most rapidly toward the full and nearly full moons and making them move north and rise relatively sooner each day.
 
Note that’s relatively sooner. The moon’s orbit makes it rise later from one day to the next; on average, around 50 minutes later. But around the time of the fall equinox, that interval gets slashed because of the moon’s rapid movement up through the northern sky. This year, for a few days centered on September 24, moonrise comes only 24 minutes later each night. That’s the harvest moon effect.
 
It’s fortunate for farmers, because it means that near full moon time, farmers harvesting crops don’t have to wait as long for a bright moon to come up and light their fields.
 
Finally, the rapid change in Earth’s tilt is sapping the day length faster than ever at this time of year, which I’m sure comes as no surprise. We’re losing around three minutes of daylight every day. But, I keep reminding myself, people in places like Alaska and Iceland have to put up with losses of six minutes a day.

 

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Northern Sky: Sept 1 - 14, 2018

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

She tells us what to look for in the night sky in our region.

NORTHERN SKY – by Deane Morrison                      September 1-14 2018
 
Now that September’s here, the skies are getting seriously dark. Venus is still in the west, but it’s sinking fast. It’s also coming toward us, on the way to zipping between Earth and the sun. If you have a small telescope, you can watch it go through phases. Venus appears as a fat crescent now, but the crescent gets longer and thinner as September goes by. 
 
Somewhat high in the west, we have the brilliant star Arcturus. At this time of year, I like to watch Arcturus slowly fall through the sky from night to night. Arcturus is the brightest star in Bootes, the herdsman, a kite-shaped constellation, and it’s right where the tail of the kite would attach to the sail. So as Arcturus and Bootes drop down toward the horizon, it always seems as if this heavy star is dragging the kite down with it.
 
Actually, Arcturus is falling on a grander scale. It doesn’t orbit horizontally around in the disk of the Milky Way like the sun. Instead, its orbit slices right through the galactic disk. But Arcturus isn’t plunging through the disk by itself; it has more than four dozen stellar companions. Together the group is called the Arcturus stream. One caution: Don’t confuse Arcturus with Jupiter, which is bright but rather low in the southwest after nightfall.
 
Mars and Saturn come out low in the south. Mars is east of Saturn; it’s also brighter and, of course, redder than Saturn. Between the two planets is the Teapot of Sagittarius. Above all this, we have the large Summer Triangle of bright stars. The lowest is Altair, in Aquila, the eagle. It’s pretty much right above Mars. Looking up and a little west of Altair, you’ll see the brightest star in the Triangle. That’s Vega, in Lyra, the lyre of Orpheus. Note the parallelogram of stars below Vega; they outline the lyre and they make a really beautiful sight through binoculars. East of Vega is the third star, Deneb, in Cygnus the swan. Deneb also marks the head of the Northern Cross, a notable feature of Cygnus.
 
The Summer Triangle is a rich area of sky to explore, with both the naked eye and binoculars. And a star chart, if it’s your first time. Look above Altair—again, that’s the lowest star in the Triangle—and try to make out a short and skinny constellation called Sagitta, the arrow. Then try immediately northwest of Sagitta’s feathers and see if you can find the dim but astonishingly realistic Coathanger hanging upside-down. You’ll need those binoculars to make it out. Finally, look to the east-northeast of Altair for Delphinus, the dolphin, which seems to be happily leaping into a dark sea.
 
The moon is new on September 9.  For a couple days before then, there’s a thin old crescent moon in the east before dawn. On Saturday, the 8th, the moon rises close to Regulus, the brightest star in Leo. Then comes Mercury, and the sun right behind it. Look about 40 minutes before sunrise, and good luck seeing all three of the other objects when the sun is so close.
 
And, starting on the 8th, try looking for the elusive zodiacal light in the east, just before the sky starts to get light. The zodiacal light appears as a broad but faint glow along the sun’s path and it comes from sunlight reflecting off the dust that extends far out into space in the plane of the solar system. If you don’t find the zodiacal light on the 8th, the following two weeks will also be good times to look, and the moon won’t interfere with your view of the morning sky. 

 

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