Venus and the Pleiades
This weekend, the planet Venus will have a rare close encounter with the Pleiades star cluster.
Venus is just the opposite. Dazzling, bright enough to cast faint shadows, it beams down from the heavens and grabs you, mesmerizing. You can't take your eyes off it.
This weekend, Venus and the Pleiades are coming together. It happens every 8 years: Venus glides through the Pleiades star cluster and, while dissimilar things don't always go well together, these do. It's going to be a beautiful ensemble.
Above: Venus, Mars and the Pleiades. Charles Kiesel of Fort Branch, Indiana, took the picture on April 1, 2004, using a Canon A40 camera, 100-speed film, and a 10s exposure.
Step outside after dark on Thursday, April 1st and look west. Venus is the improbably-bright "star" about halfway up the sky. Just above Venus lies the Pleiades, often mistaken for the Little Dipper because the faint stars of the Pleiades trace the shape of â€Ś a little dipper.
Here are a few things to think about while you're watching the show:
The Pleiades are a clutch of baby stars. They formed barely 100 million years ago, during the age of dinosaurs on Earth, from a collapsing cloud of interstellar gas. The biggest and brightest of the cluster are blue-white and about five times wider than our own sun.
Above: The western sky after sunset on April 2, 2004, as viewed from mid-northern latitudes. More sky maps:, , , , 2004.
The Pleiades didn't exist when Venus first emerged from the protosolar nebula 4.5 billion years ago. No one knows what Venus was like in those early days of the solar system. It might have been lush, verdant, Earth-like. Today, though, it's hellish. A runaway greenhouse effect on Venus has super-heated the planet to nearly 900° F, hot enough to melt lead. Dense gray clouds laced with sulfuric acid completely hide Venus' surface from telescopes on Earth. The smothering clouds, it turns out, are excellent reflectors of sunlight, and that's why Venus looks so bright.
As seen from Earth, Venus shines about 600 times brighter than Alcyone, the most luminous star in the Pleiades. During the weekend try scanning the group with binoculars. You'll see dozens of faint Pleiades invisible to the unaided eye. Among them, bright Venus looks like a supernova.
But, really, it's just an ancient planet gliding in front of some baby stars--a dissimilar ensemble that you won't want to miss.