Astronomy Picture of the Day

Explanation: Denizens of planet Earth watched last year's Perseid meteor shower by looking up into the bright moonlit night sky. But this remarkable view captured on August 13, 2011 by astronaut Ron Garan looks down on a Perseid meteor. From Garan's perspective onboard the International Space Station orbiting at an altitude of about 380 kilometres, the Perseid meteors streak below, swept up dust left from comet Swift-Tuttle heated to incandescence. The glowing comet dust grains are traveling at about 60 kilometres per second through the denser atmosphere around 100 kilometres above Earth's surface. In this case, the foreshortened meteor flash is right of frame centre, below the curving limb of the Earth and a layer of greenish airglow, just below bright star Arcturus. Want to look up at this year's Perseid meteor shower? You're in luck. This weekend the shower should be near its peak, with less interference from a waning crescent Moon rising a few hours before the Sun.