Above and Beyond

Red and green northern lights flicker silently across the starry night sky over Peyto Lake in the Canadian Rocky Mountains near Banff. Shortly before moonrise the moon is painting the northern horizon in yellow.
The diffuse ethereal glow of the green and pink aurora borealis spread out along the northern and northeastern horizon during the night of the new moon. This phenomenon is caused by particles flung out by the sun at enormous speed. Guided by Earth’s magnetic field towards the poles, they collide with atoms in the thin atmosphere at an altitude of 60 to 190 miles (100 to 300 km) above the Earth’s surface. Within the ionosphere, the absorbed energy is emitted as visible light. The green and red colors are emitted when the suns particles collide with atomic oxygen in the atmosphere. Purple colors result from collisions with molecular nitrogen.
Ursa Major, the Big Dipper, is visible just atop the pink northern lights and the Corona Borealis, the Northern Crown, to its left. Peyto Lake is located in the glacial valley below Bow Pass. The lake is fed by meltwater of the Peyto glacier.
The stream carries vast amounts of sediments and rock flour into the lake. The latter causes the lakes beautiful and famous blue-green waters, even visible at night.

August 2009
Canon 5D MkII, Canon EF-L 16-35mm, f/2.8, 6 minutes static and dynamic images, ISO 1600, tripod, AstroTrac TT320 astronomical mount
Rocky Mountains Gallery » Above and Beyond