March 2012 shows off all five visible planets in the evening sky. You can catch these planets in the evening hours, possibly before your bedtime. By visible planet, we mean any planet that’s easy to see without an optical aid and that has been observed by our ancestors since time immemorial. In their outward order from the sun, the five visible planets are Mercury, Venus, Mars, Jupiter and Saturn.
Four of the five visible planets pop out at dusk: Mercury, Venus, Jupiter and Mars. You’ll have to wait until mid to late evening before the fifth planet – Saturn – comes up over the eastern horizon. Saturn rises in the east about an hour before Jupiter sets in the west. If you have a clear horizon, you might be able to see Jupiter and Saturn in the same sky together for a half-hour or more.
Shortly after sunset, look for Venus and Jupiter to blaze away in the western sky. If it’s clear, you simply can’t miss these worlds, for Venus and Jupiter rank as the third-brightest and fourth-brightest heavenly bodies, respectively, after the sun and moon.
Draw an imaginary line downward from Jupiter and past Venus to locate Mercury by the horizon. (See the chart at the top of page.) Mercury may appear visible to the unaided eye about 45 to 75 minutes after sunset. Although Mercury shines as brilliantly as a first-magnitude star, binoculars may help you to spot Mercury in the haze of evening twilight. At mid-northern latitudes, Mercury sets about 90 minutes after sundown.
The brilliant ruddy planet Mars rises in the east before Mercury sets in the west. Mars now shines from nightfall till dawn, easily outshining nearby Regulus, the constellation Leo’s first-magnitude star.
If waiting until 9:30 to 10:30 p.m. to view Saturn is too late for you, try later this month. By the end of March, Saturn will climb above the eastern horizon a short while after nightfall. Throughout 2012, golden-colored Saturn shines in the vicinity of blue-white Spica, the constellation Virgo’s first-magnitude star.
Watch for the great planetary attraction to light up the March 2012 sky, as the grand procession of visible planets may well be yours to behold before bedtime tonight.