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.

March 17, 1999
See Explanation.  Clicking on the picture will download 
 the highest resolution version available.

Ice Fishing for Cosmic Neutrinos
Credit & Copyright: The AMANDA Collaboration

Explanation: In 1996, scientists melted a hole in the bottom of the world. In fact, several holes have been melted near the South Pole, and they are now being used as astronomical observatories. Astronomers with the Antarctic Muon and Neutrino Detector Array (AMANDA) lower into each vertical lake a string knotted with basketball-sized light detectors. The water in each hole soon refroze. The detectors are sensitive to blue light emitted in the surrounding clear ice. Such light is expected from ice collisions with high-energy neutrinos emitted by objects or explosions out in the universe. The above picture was taken 750 meters below the surface looking down into the abyss. Instruments were lowered down past 2000 meters. Data from AMANDA is already being collected and analyzed.

Tomorrow's picture: Messier Marathon

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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
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