Night of the Transit
Perhaps you just watched the 2012 transit of Venus until the sun set on the western horizon. What a spectacle! Savor the moment as if it were a fine meal, for a tasty dessert is about to follow. As sunset segues into twilight, planets are about to emerge in the western sky. Since your telescope is already set up and an eager crowd has gathered, seize this opportunity to share a view of ruddy Mars, graceful Saturn, and other celestial highlights.
Because it is so near the sun (which set around 9:15 p.m. daylight time for mid-northern latitudes), Mercury is lost in the evening glare (shown). By 10:00 p.m., Saturn is readily apparent as it hovers above the star Spica in the constellation Virgo. Mars looms to the right at the same brightness, magnitude=0.6.
When darkness deepens, marvel at the ever-inspiring rings of Saturn, a vast yet ultra-thin disk of ice particles encircling the planet. The ringed planet is inclined more than two degrees, and several of its moons are visible in modest telescopes, simulated at left.
(click to enlarge)
As the hours pass and night settles in, the splendor of the summer constellations take center stage. Deep space objects become targets for the telescope. Shortly after midnight, a large gibbous moon rises with the constellation Sagittarius, near the heart of the Milky Way galaxy. Though the moon washes out faint stars, you can still sense the magnificence of our cosmos.
Six months later, the sun will be poised in this same region by day, overwhelming the background constellations completely. Somehow this situation portends a doomsday scenario for apocalypse-minded fear-mongerers. (See article 2012 Doomsday and Solar System Alignment, which features a 2012 Survival Guide.) For tonight, on the heels of the 2012 transit of Venus, celebrate the predictive nature of real astronomy, and how the fusion of math and science has allowed humans to quantify our place in space by timing the duration of a rare dance of the planets, as witnessed from across the globe.
The next transit of Venus awaits us in December 2117.
To see current highlights of the night sky, including satellite passes and star charts, see