December 12, 2006 [LINK / comment]

Triple play! Planets converge

Jupiter, Mercury and Mars Alerted by the monthly "Skywatch" column in the Washington Post, I went planet gazing before dawn this morning, and soon spotted Jupiter, Mercury, and Mars very close to each other, hovering right above the orange-hued eastern horizon. I couldn't see any of Jupiter's moons this time, probably because the skies were beginning to brighten. Unfortunately, the Post didn't mention that there won't be another close convergence of three such bright planets until 2053. If I'd known that, I would have made a point to be outside early on Sunday morning, when the planets were closest together. All three planets are approaching the sun, as seen from Earth, and the quick-moving Mercury will disappear from our view in the next couple days. For more on this rare celestial event, see space.com.

Roll mouse over this image to see what it looked like on Sunday morning, when the convergence occurred. Arrows indicate relative velocity. The stars labeled with green Greek letters are in the constellation Scorpio. Modified image from Amateur Astronomers Association of New York.