University of Minnesota
University of Minnesota

Minnesota Starwatch

University of Minnesota

Minnesota Institute for Astrophysics

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Starwatch Newsletter

Minnesota Starwatch is a newsletter describing the night sky in the Midwest. It is updated monthly, and is produced by the
Minnesota Institute for Astrophysics, University of Minnesota
116 Church Street SE, Minneapolis, MN 55455

Minnesota Starwatch for May 2012

by Deane Morrison

May is full of delights, starting with a full moon on the 5th.

This moon, known to Algonquin Indians as the flower moon, milk moon or corn planting moon, rises only about two hours before the moment of perfect fullness, which comes at 10:35 p.m. Not only that, but the moon will be at perigee—its closest approach to Earth in its orbit—only three minutes before fullness, so it will be not only round but big, although the size difference may well be imperceptible.

Venus is busy this month taking a spectacular plunge into the sun's afterglow. Through a small telescope or even a pair of steady binoculars, you can see the planet's crescent shape as it wanes away.

On June 5, Venus will make a rare "transit" right across the face of the sun. The University's Institute for Astrophysics will hold a public program about the event from 4 to 5 p.m. that day in Room 166 Tate Laboratory, 116 Church St. S.E., Minneapolis. From 5:30 p.m. till sunset, the public is invited to view the transit on the roof of the building. If the weather is cloudy, there will be a live feed from Hawaii in Room 166. For more information, see

Mars and Saturn are front and center in the south after nightfall. Mars is higher and in the south-southwest. Just to the northwest of Mars is Regulus, the brightest star in Leo. Saturn, in the south-southeast, is also paired with a bright star; its companion, shining just below the planet, is Spica, in Virgo. High above Saturn and Spica is Arcturus, the brilliant beacon in Boötes, the herdsman.

On the 20th, we're treated to a partial eclipse of the sun. The show begins at approximately 7:15 p.m., and the sun will set while still in a state of partial eclipse. A little more than half its surface will be covered by the moon. The usual warnings about solar eclipses apply: do not look at the sun without proper protection. If you're unsure—don't look. The safest way to view a solar eclipse is with a pinhole camera—or on TV.

Whether partial or total, solar eclipses always occur at the time of a new moon, when the moon is gliding between Earth and the sun. Usually, the moon passes either north or south of the sun. But since the orbits of Earth around the Sun and the Moon around the Earth aren't aligned, their paths cross; the intersections are called nodes. Solar eclipses happen when a new moon crosses a node. When a full moon does, we get a lunar eclipse.

If skies are dark, see if you can make out the star pattern called the Three Leaps of the Gazelle. It comprises three evenly spaced pairs of stars between the bowl of the Big Dipper and the curved Sickle of stars outlining Leo's head.


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: 

Twin Cities, Minnesota Institute for Astrophysics (during fall and spring semesters): 

4/20/12 Contact: Deane Morrison, University Relations, (612) 624-2346,