University of Minnesota
Starwatch July 2012
By Deane Morrison
The July sun keeps starwatching hours short, but the planets and summer stars keep things hopping.
Mars, the fastest of the outer planets, staves off its inevitable tumble into the sun's afterglow by speeding eastward toward Saturn, which appears above the bright star Spica, in Virgo. Between the 23rd and the 25th, a young crescent moon glides below Mars, the westernmost of the three, then the Spica-Saturn pair.
During the prime viewing hours of late evening, you'll see kite-shaped Bootes, the herdsman, high in the west. East of Bootes come, in order, Corona Borealis, the Northern Crown; upside-down Hercules; the brilliant star Vega, in Lyra, the lyre; and lovely Deneb in Cygnus, the swan. South of Vega and Deneb shines Altair, the brightest star in Aquila, the eagle. Together, these three stars are known as the Summer Triangle.
In the south, S-shaped Scorpius stretches its claws westward, toward dim Libra, the scales. The scorpion's most prominent feature is its heart, Antares, a star classified as a red supergiant and having a diameter about 700 times that of our sun. It's a good thing Antares is a distant 500 light-years away, because it shines with the light of 10,000 suns.
And speaking of shining, Venus, having transited the sun in grand fashion on June 5, is now in the morning sky. The planet appears in the east, outblazing Jupiter, which hovers above it. On the 15th, a waning crescent moon visits the pair. Near them is the orangish star Aldebaran, the eye of Taurus, the bull.
The full buck moon arrives at 1:52 p.m. on the 3rd. Its name comes from the velvety new antlers now sprouting on male deer. Algonquin Indians also called it the full thunder moon, in recognition of July's frequent thunderstorms.
Earth reaches aphelion, its farthest point from the sun, at 10:33 p.m. on the 4th. At that moment we'll be 94.5 million miles from our parent star.
If you'd like a first-person introduction to the night sky, check out the University of Minnesota's Minnesota Institute of Astrophysics summer Universe in the Park program. Each event features a short public talk and slide show by a U of M astronomer and, if weather permits, viewing the night sky through multiple 8-inch telescopes. The program runs Fridays and Saturdays through August 25 this year in Minnesota state parks. For more information and a schedule, visit http://www.astro.umn.edu/outreach/uitp/ or contact Jennifer Delgado at email@example.com or (612) 626-2275.
The University of Minnesota offers public viewings of the night sky at its Duluth campus. For more information and viewing schedules, see:
Duluth, Marshall W. Alworth Planetarium: www.d.umn.edu/planet
Check out the astronomy programs at the University of Minnesota's Bell Museum ExploraDome: www.bellmuseum.umn.edu/ForGroups/ExploraDome/index.htm
5/22/12 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 http://www.astro.umn.edu.