For several weeks now, the brilliant planet Jupiter has ruled our evening sky as its brightest object, but Jupiter's reign is about to come to an end. Emerging from out of the evening twilight and into our evening sky is the dazzling Queen of the Night, the planet Venus.
It's been a whole year since Venus last graced our evening sky, having spent last fall, winter and spring as our "morning star" before dawn. You can spot Venus tonight, in the colorful evening twilight, if you have a clear view of the western horizon. The best time to catch her is between 8:15 and 9 p.m. because she sets about one hour after the sun does. With each passing night, Venus is climbing higher and higher out of the twilight and setting later each evening. Soon, she'll be seen in a totally darkened sky, and Jupiter will pale by comparison.
During the next two weeks, Venus will pair up with the planet Mercury for some fancy planet dancing. The two planets will execute a celestial do-si-do in the western sky between mid-August and mid-September. Their first close pass happens on Wednesday evening when the pair will be a little less than 1 degree apart. Use binoculars to enhance the view. Mercury then performs a 3-week-long loop below Venus and returns to pass 3.5 degrees from her again on the night of Sept. 11. On that same night, the planet Mars, which has been hovering in the distance, will appear only 14 degree below Venus. It isn't often that you can see the planets Venus and Mars through your telescope eyepiece at the same time. Give it a try.
Perhaps the most stunning scene in this dance of planets come on the evening of Sept. 1, when the 2-day old crescent moon joins Venus, Mercury and Mars for a planetary grouping that you won't soon forget. With the Earth in the foreground, you'll be able to see all four of the terrestrial planets in our solar system, plus the moon, in one glance.
As the days of summer and then autumn fall from the calendar, the sky's two brightest planets, Venus and Jupiter, will draw closer and closer together. They are destined to rendezvous on the night of Dec. 1 with another slender crescent moon for a beautiful end of the year holiday conjunction.
Professor Jimmy Westlake teaches astronomy and physics at Colorado Mountain College's Alpine Campus. He is an avid astronomer whose photographs and articles have been published on the Web sites of CNN.com, NASA's "Astronomy Picture of the Day" Web site, Spaceweather.com, Space.com, Discover.com, MSNBC.com, NationalGeographic.com, and in Sky & Telescope, Astronomy, Night Sky, Discover, and WeatherWise magazines. His "Celestial News" article appears weekly in the Steamboat Pilot & Today.