Astronomy Picture of the Day

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.

September 9, 1999
See Explanation.  Clicking on the picture will download 
 the highest resolution version available.

Comet Hale-Bopp Over the Superstition Mountains
Credit & Copyright: William R. Dellinges

Explanation: Four years ago, Comet Hale-Bopp was discovered out near Jupiter falling toward the inner Solar System. Two years ago, it provided spectacular pictures as it neared its closest approach to the Sun. Still today, spectacular pictures of the brightest comet of the 1990s are surfacing. Above, Comet Hale-Bopp was photographed in 1997 behind the Superstition Mountains in Arizona. Clearly visible are the comets white dust tail that shines by reflected sunlight, and the blue ion tail that shines by glowing gas. Currently, there are several comets visible from the proper location with a small telescope. A comet visible to the unaided eye appears about once every five years.

Tomorrow's picture: Cassini Moon Images

< Archive | Index | Search | Calendar | Glossary | Education | About APOD >

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Technical Rep.: Jay Norris. Specific rights apply.
A service of: LHEA at NASA/ GSFC
& Michigan Tech. U.