Minnesota Starwatch for July 2005
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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
Department of Astronomy, University of Minnesota
116 Church Street SE, Minneapolis, MN 55455

Minnesota Starwatch for July 2005

Welcome to Minnesota Starwatch for July 2005 - a month of terrestrial and celestial fireworks -- more on that later. New Moon is July 6th, with Full Moon on the 21st. One of the more colorful names for July's full moon is Sturgeon Moon, because of the ease of catching them in bodies of water like the Great Lakes. At dusk, you can find Venus low in the western sky. Far to the upper left of Venus is bright Jupiter, and its angle in the sky provides for fine views of eclipses of its own moons, which you can see by watching night-to-night with good binoculars or a small telescope. Rising around midnight in the constellation of Pisces is neighbor Mars. It will become even brighter and bigger in the following months as it comes closest to the Earth. On the night of July 17-18, look for the Moon low in the sky - nearby you will find the very red star Antares, the brightest star in the constellation of Scorpius. From the Southern U.S., the Moon will occult, or block the light from Antares, while from Minnesota we will just see the two objects close together. A close encounter is just what occurred on July 4th, when the Deep Impact probe collided with the periodic comet Tempel 1, after a 6 month journey from Earth. Over the next months and years, the data from this exciting experiment will be teaching us about the material deep within the comet nucleus, an odd shaped, cratered body only four miles across. The journey to Tempel 1 was a true tour de force -- hitting the target after traveling 100 million miles. This is like shooting something across the entire United States and hitting a target less than 1 foot across. And just to make things more difficult, the target and the spacecraft were travelling by each other at about 7 miles every second, so the navigation and the pointing had to be incredibly precise. Comets are exciting to study because they represent the original material out of which the solar system was made. What we see on the Earth has been processed through the Earth's long and complicated geological history, through melting, convection, chemical separation and a variety of other processes. Comets, on the other hand, are pretty much as they formed 4.5 billion years ago, a little worse for wear perhaps by coming near the Sun, which boils off their volatile materials, and by impacts from chunks of asteroid and other debris in space. But Deep Impact has now sprayed fresh new material into space, for us to study and learn about our origins. The NASA website, http://deepimpact.jpl.nasa.gov/home/index.html,. is a wonderful resource to find out more about this unique mission. For fun Astronomy Outreach programs check out our Public Outreach link, or if you're interested in how you can help build the new Minnesota Planetarium, please call 612-630-6151 or visit http://www.mplanetarium.org. Como Planetarium is offering fun family shows about astronomy on a limited basis; please call 651-293-5398 for more info! This has been a Minnesota Starwatch produced by the University of Minnesota Astronomy Department.