Planets put on a show

Published 7:01 am Sunday, May 31, 2015

By Deane Morrison

University of Minnesota

In June the approach between Venus and Jupiter culminates in the two brightest planets finally meeting over the western horizon.

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They begin the month 20 degrees apart in the west, with Jupiter closing in on Venus from the northeast. On the 1st and 2nd, Venus makes a nearly straight line with the Gemini twins Pollux and Castor, which twinkle just west of the planet. But the line breaks up as the stars, left behind by Earth’s orbital moon, head toward the sunset.

On the 2nd through the 4th, we have a great chance to find the lovely but elusive Beehive star cluster, when it will be midway between Jupiter and Venus. Look an hour and 45 minutes after sunset and use binoculars to see the cluster, whose Latin name is Praesepe, or manger. Just east of it you’ll see two stars; these are the Aselli, or asses, feeding at the manger. On the 12th and 13th, the Beehive passes about a degree to the southeast and south of Venus. This pair will be beautiful; again, look an hour and 45 minutes after sunset.

On the 30th, the great approach ends as Jupiter sweeps within 0.3 degrees, or just over half a full moon width, from Venus. The view will be terrific through binoculars or a small telescope. The planets are near the horizon and set soon after dark, so you may have to plan your viewing to be sure of catching them.

Saturn comes out low in the east to southeast after nightfall, just west of the claws of Scorpius. Compare its golden color to that of Antares, the scorpion’s giant red heart southeast of the ringed planet, and also to Jupiter and Venus.

The brilliant star Arcturus comes out high in the south, above and slightly west of Saturn. Extending from Arcturus toward the northeast is the bulk of its constellation: kite-shaped Bootes, the herdsman. East of Bootes hangs the semicircle of stars called Corona Borealis, the northern crown; the jewel in this diadem is Alphecca. Moving east again, Hercules, marked by an hourglass of stars, hangs upside down. And finally, the Summer Triangle of bright stars shines east of Hercules, who is best seen with the aid of a star map.

June’s full moon arrives at 11:19 a.m. on the 2nd, hours after setting. Look for it in the west about an hour before sunrise that morning, or in the east around sunset that night. This moon was known to Algonquin Indians as the strawberry moon, whereas Europeans called it the rose moon.

The summer solstice arrives at 11:38 a.m. on the 21st, when the sun reaches a point directly above the Tropic of Cancer. At that moment a traveler in space would see Earth lighted from the Antarctic Circle on the sunny side to the Arctic Circle on the far side.

The University of Minnesota offers public viewings of the night sky at its Duluth and Twin Cities campuses. For more information and viewing schedules, see:

Duluth, Marshall W. Alworth Planetarium: www.d.umn.edu/planet
Twin Cities, Minnesota Institute for Astrophysics (during fall and spring semesters): www.astro.umn.edu/outreach/pubnight.
Check out the astronomy programs at the University of Minnesota’s Bell Museum ExploraDome: www.bellmuseum.umn.edu/ForGroups/ExploraDome/index.htm.

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