Welcome to Nightwatch, Adler Planetarium's monthly sky-watching guide for July 2008.

The first half of the month, theres lots of action in the evening sky just above the western horizon. The planet Mars moves quickly through the sky each passing night. On the 1st it's a degree away from Regulus, brightest star in the constellation Leo. Over the next several nights Mars moves to within a degree of the planet Saturn. The two are at their closest the evening of the 10th. Saturn is the brighter of the two. The evening of the 5th is particularly exciting, with a three-day-old crescent Moon, Regulus, Mars, and Saturn - all within a line only about 11 degrees long. The evening of the 6th, the waxing crescent Moon is a few degrees south of the line-up. By mid-month, the line-up is moving apart and is dropping lower in the west in evening twilight. Late in the month, if you have a clear west-northwest view, you might be able to spot the planet Venus very low on the horizon shortly after sunset.

On the other side of the sky, the bright planet Jupiter rises in the southeast during evening twilight. Jupiter's brightness, and the fact that it's up in the south nearly all night long, makes up for it not getting very high in the sky this month. It sets in the southwest by morning twilight. On the 16th and 17th, Jupiter is not far from the nearly full Moon.

Early risers with a clear view to the east-northeast horizon might be able to catch a glimpse of the planet Mercury the first half of this month. At its highest it's only about ten degrees above the horizon in morning twilight. It's higher in the sky the first week of the month, and lower but brighter in magnitude the second week. By the third week the light of dawn obscures it.

The New Moon is on the 2nd. The First Quarter is on the 9th. The Full Moon is on the 18th, and the Last Quarter is on the 25th.

Thanks for visiting Nightwatch, updated monthly with the assistance of Starry Night software. To learn more about this month's sky, visit us on the web, at www.adlerplanetarium.org. And, for astronomy news to-go, download the "Adler Night and Day" podcast. For directions on how to subscribe to the podcast series, go to www.adlerplanetarium.org/podcasts -- or, search for "Adler Night and Day" on iTunes.

Ever been to a star party? People of all ages enjoy the exciting hobby of amateur astronomy! Local amateur astronomy clubs provide opportunities for beginning, advanced and family skywatchers to observe the heavens from dark sky sites, learn to use telescopes and astrophotography equipment, and take trips to star parties around the country. Check out the Adler's database of amateur astronomy clubs in the Chicago area to find out more.