Astronomy Picture of the Day

Explanation: In this striking image, a rocket climbs skyward toward an expansive green auroral display in the first launch of 2003 from the University of Alaska's Poker Flat Research Range. Recorded on January 27th, the view from Cleary Summit near Fairbanks, Alaska shows the fiery tracks of both solid fuel stages of the Black Brant IX sounding rocket that lofted its payload to an altitude of 385 kilometres. Compared to rockets which launch payloads to Earth orbit and beyond, sounding rockets are small and relatively inexpensive. They get their generic name from the nautical term "to sound" which means to take measurements. Known as HIBAR (HIgh Bandwidth Auroral Rocket), this experiment was designed to measure aurora related high-frequency plasma waves which may originate thousands of kilometres above the aurora's visible glow.