Wyoming Skies for October

September 30, 2009 — A monthly look at the night skies of Wyoming, written by Ron Canterna, professor in the University of Wyoming Department of Physics and Astronomy.

The transition from the summer to winter constellations occurs during October. The summer triangle, which connects the bright stars Vega, Deneb and Altair, is overhead after sunset and gradually sets at midnight.

A very beautiful object for small telescope observers is the "Ring Nebulae" lying very close to Vega. The next constellation we will see directly overhead is the Great Square of the constellation Pegasus, the Winged Horse. Notice four modest stars that comprise the Great Square.

Between Pegasus and Cassiopeia (the stretched out "M" or "W" at our zenith) is the Chained Lady, Andromeda. The Great Andromeda Galaxy, called M 31, lies within the confines of this constellation and is the only naked-eye object in the northern sky that does not belong to our Milky Way galaxy. It is a great object for binocular views.

Jupiter can be seen in Capricorn in the southeast at sunset and during the remainder of the evening. Mars rises at midnight and is in Gemini. The Orionids meteor shower peaks during Oct. 20-24 and we should see about 20 meteors per hour. It is best seen in the morning.

October 2009 Interest: Water on the Moon: I

Ten years ago, Dr. Faith Vilas, now the director of the Multi-Mirror Telescope in southern Arizona, looked at archival data for the moon from the Galileo satellite mission, which concentrated on investigating the planetary environment of Jupiter and its natural satellites. What Vilas found was extraordinary. She noticed that the south pole of the moon showed evidence for the presence of minerals normally associated with water. The infrared signal of these phyllo-silicate minerals was clearly present.

Moreover, these minerals normally need heat and water to form. Like all good scientists, after carefully considering all the consequences of an important and unexpected discovery, she submitted her findings for publication.

Her work was not accepted initially. It was not until the recent growing evidence from other satellite missions showed that water is indeed present on the moon that her discovery was accepted for publication. As we all know now, Vilas was correct in her findings and she may be "laughing all the way to the bank," -- the bank of unexpected first-time discoveries. She should be applauded for her persistence and dedication. (More in November's column on the nature of the lunar water.)

For more information, visit the Wyoming Skies home page (http://wyoskies.uwyo.edu ) or send an e-mail to canterna@uwyo.edu.

Posted on Wednesday, September 30, 2009