Astronomy Picture of the Day

Explanation: There's a hole in the bottom of the world. In fact, there are several holes, and they are being used as astronomical observatories. Scientists with the Antarctic Muon and Neutrino Detector Array (AMANDA) project dig these holes thousands of meters deep into the South Pole ice. Lowered into each hole is a string knotted with basketball-sized light detectors. 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 an abyss over 2000 meters deep. Data from AMANDA is already being collected and analyzed.