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. 2015 September 1



Distant Neutrinos Detected Below Antarctic Ice

Image Credit: IceCube Collaboration, U. Wisconsin, NSF

Explanation: From where do these neutrinos come? The IceCube Neutrino Observatory near the South Pole of the Earth has begun to detect nearly invisible particles of very high energy. Although these rarely-interacting neutrinos pass through much of the Earth just before being detected, where they started remains a mystery. Pictured here is IceCube's Antarctic lab accompanied by a cartoon depicting long strands of detectors frozen into the crystal clear ice below. Candidate origins for these cosmic neutrinos include the violent surroundings of supermassive black holes at the centers of distant galaxies, and tremendous stellar explosions culminating in supernovas and gamma ray bursts far across the universe. As IceCube detects increasingly more high energy neutrinos, correlations with known objects may resolve this cosmic conundrum -- or we may never know.