Astronomy Picture of the Day
    


Space Station Detector Finds Unexplained Positron Excess
<< Yesterday 6.10.2014 Tomorrow >>
Space Station Detector Finds Unexplained Positron Excess
Credit & Copyright: Ron Garan, STS-134 Crew, Expedition 28 Crew, NASA
Explanation: Where did all these high energy positrons come from? The Alpha Magnetic Spectrometer (AMS-02) onboard the International Space Station (ISS) has been meticulously recording how often it is struck by both high energy electrons and positrons since 2011. After accumulating years of data, it has now become clear that there are significantly more positrons than electrons at the highest energies detected. The excess may have a very exciting and profound origin -- the annihilation of distant but previously undetected dark matter particles. However, it is also possible that astronomical sources such as pulsars are creating the unexplained discrepancy. The topic remains a very active area of research. Pictured here, the AMS is visible on the ISS just after being installed, with a US Space Shuttle docked on the far right, a Russian Soyuz capsule docked on the far left, and the blue Earth that houses all nations visible across the background.

Follow APOD on: Facebook, Google Plus, or Twitter

January
February
March
April
May
June
July
August
September
October
November
December
 < October 2014  >
Mo Tu We Th Fr Sa Su


12345
6789101112
13141516171819
20212223242526
2728293031

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.

Based on Astronomy Picture Of the Day

Publications with keywords: ISS - dark matter
Publications with words: ISS - dark matter
See also:
All publications on this topic >>