University of Minnesota
May 17, 2011
In this image from February 24, 2009, Saturn's giant orange moon Titan and its shadow grace the face of the planet. The tiny dot above the rings is the moon Dione.
Image: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)
By Deane Morrison
Treats are in store for us at both ends of the short summer nights this June.
Evenings belong to Saturn, a beacon in the southwest. Not sure which object is the ringed planet? Look the evening of the 10th, when a waxing moon sits below and between the bright star Spica, in Virgo, to the east and Saturn to the west.
Northeast of Saturn shines brilliant Arcturus in Bootes, the ploughman. Just east of Bootes hangs Corona Borealis, the Northern Crown, set off by its brightest star, Alphecca (also called Gemma). Moving east once again, we see the upside-down form of Hercules with its signature hourglass shape.
Low in the south, the sinuous form of Scorpius scrapes the horizon as it reaches toward the rather mundane form of Libra. Note the scorpion's red heart, Antares, which boasts a diameter 700 times that of our sun and ranks among the largest stars known.
If the sun were as big as Antares, it would extend well beyond the orbit of Mars, almost to the halfway point between Mars and Jupiter. But Antares was not always so big; it expanded as it aged, and now belongs to a class of old stars called red supergiants. By about five billion years from now our sun will also begin to expand as it nears the end of its life, but it will become a red giant—not supergiant—and so won't balloon up to nearly the extent as Antares. Still, it will likely engulf the Earth, but by that time our oceans, lakes and rivers will long since have boiled away.
Directly east of Scorpius, the Teapot of Sagittarius is poised to pour its contents onto the scorpion's tail. And don't miss the tiny Teaspoon of stars sitting above the Teapot's handle.
Morning treats start with the rising of Jupiter, about two hours before sunup on the 1st and earlier every day thereafter. Its brilliant yellowish globe climbs quickly and dominates the eastern predawn sky.
Mars follows Jupiter, but climbs slowly. Look for the Red Planet on the 28th, when the eastern sky will be stacked (from top to bottom) with the Pleiades star cluster, a waning crescent moon, Mars, and the combination of the V-shaped Hyades cluster and yellowish Aldebaran, the eye of Taurus.
Every Algonquin tribe called June's full moon the full strawberry moon, and it shines the night of June 15-16.
Summer arrives officially with the solstice at 12:16 p.m. CDT June 21. At this moment the sun reaches a point directly over the Tropic of Cancer and the Northern Hemisphere experiences the longest day of the year.
The Marshall W. Alworth Planetarium at the University of Minnesota, Duluth sponsors free public shows. For more information, see www.d.umn.edu/planet
Contact: Deane Morrison, University Relations, (612) 624-2346, firstname.lastname@example.org
Find U of M astronomers and links to the world of astronomy at www.astro.umn.edu