Monumental Leonid Storm

From the photographer: “Taken during the great Leonid meteor storm of November, 2001, as fireballs streaked over Monument Valley on the Utah/Arizona border. Fuji 800 film at f/1.8, 34 second exposure. Digital scan by Tony Hallas.

The red and green color often seen in photos of bright meteors is thought to be due to the ionization of air molecules at different altitudes, with a green glow being produced by oxygen higher up, and the red by nitrogen lower down. Though invisible to the naked eye, the faint colors can persist long enough to be picked up by a camera. A much brighter example of red and green ionization can be seen in the auroras, the so-called Northern and Southern Lights.”