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.

2016 May 23
See Explanation.  Clicking on the picture will download
 the highest resolution version available.

Inside a Daya Bay Antineutrino Detector
Image Credit & Copyright: DOE, Berkeley Lab - Roy Kaltschmidt, photographer

Explanation: Why is there more matter than antimatter in the Universe? To better understand this facet of basic physics, energy departments in China and the USA led in the creation of the Daya Bay Reactor Neutrino Experiment. Located under thick rock about 50 kilometres northeast of Hong Kong, China, eight Daya Bay detectors monitor antineutrinos emitted by six nearby nuclear reactors. Featured here, a camera looks along one of the Daya Bay detectors, imaging photon sensors that pick up faint light emitted by antineutrinos interacting with fluids in the detector. Early results indicate an unexpectedly high rate of one type of antineutrino changing into another, a rate which, if confirmed, could imply the existence of a previously undetected type of neutrino as well as impact humanity's comprehension of fundamental particle reactions that occurred within the first few seconds of the Big Bang.

Astrophysicists: Browse 1,250+ codes in the Astrophysics Source Code Library
Tomorrow's picture: diagonal peaks


< | Archive | Submissions | Index | Search | Calendar | RSS | Education | About APOD | Discuss | >

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
NASA Official: Phillip Newman Specific rights apply.
NASA Web Privacy Policy and Important Notices
A service of: ASD at NASA / GSFC
& Michigan Tech. U.