Starwatch: Get a handle on the night sky

Published 9:26 am Saturday, May 26, 2018

By Deane Morrison

University of Minnesota

Neither the Big nor the Little Dipper holds much water after nightfall in June; the Little Dipper stands on its handle while the Big Dipper hangs down by its. But the Big Dipper’s handle makes a handy guide to stars and planets.

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Follow its curve to Arcturus, the brightest star in the evening sky this month. Arcturus shines high in the south, anchoring the kite-shaped constellation Bootes, the herdsman. Continue the curve to Spica, in Virgo, then turn to the east, where Jupiter reigns over dim Libra, the scales, a constellation that resembles a jellyfish. Next to Jupiter is Zubenelgenubi. Its ancient, Arabic-derived name refers to the southern claw of Scorpius and recalls a time when stars of Libra were considered part of Scorpius. The scorpion and its red heart, Antares, rise low in the southeast and trail Jupiter into the sky.

Rising even later, Saturn glows above the Teapot of Sagittarius, the archer. On the 27th, Earth laps Saturn in the orbital race, and the planet will be up all night. Its glorious rings will be tipped to show a near-maximal amount of surface area, so if you have access to a telescope, this is a perfect time to have a look.

Trailing Saturn into the night sky, Mars brightens dramatically this month as Earth gains on it. Earth laps the red planet in the last week of July—an event not to be missed.

In the west, Venus continues to outshine everything else. On the 14th, a young crescent moon begins working its way up toward, and then past, Venus. After nightfall on the 16th, grab your binoculars and look for the lovely but subtle Beehive star cluster midway between Venus and the moon. You’ll see two stars bracketing the Beehive to the upper left; these are the Aselli, or asses. In Latin the Beehive is called Praesepe, the manger, and the Aselli are feeding at it. On the 19th, the Beehive will appear immediately southeast of Venus, but by then a nearly first-quarter moon will wash out the stars somewhat.

As Earth’s orbit carries it farther from Jupiter, the giant planet drifts westward toward Venus. Watch the gap between the two beacons narrow over the summer. Speaking of which, the summer solstice occurs at 5:07 a.m. on the 21st, as the sun reaches a point over the Tropic of Cancer.

June’s full strawberry moon arrives at 11:53 p.m. on the 27th. It won’t look very big because it will go through apogee, its farthest point from Earth in a lunar orbit, just two days later. However, since it reaches fullness in the evening, it’ll be very round as it peeks above the horizon. It glides across the night sky in company with another famous orb—Saturn.

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

Find U of M astronomers and links to the world of astronomy at www.astro.umn.edu.