Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2005 May 20
Explanation: Early last Sunday morning stars were not the only lights in Iowa skies. The northern lights also shone from the heavens, extending across the midwestern USA and other locations not often graced with auroral displays. The wide-ranging auroral activity was triggered as a coronal mass ejection - an energetic cloud of particles blasted outward from the Sun a few days earlier - collided with planet Earth's magnetosphere. Alerted to conditions ripe for aurora, photographer Stan Richard recorded this aparition over Saylorville Lake, near Des Moines. Bright planet Mars in the constellation Aquarius is above the horizon near the centre of the eastward-looking view. While the colourful rays seem to end just above the water, they are actually at altitudes of 100 kilometres or more.
Authors & editors:
NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: EUD at NASA / GSFC
& Michigan Tech. U.