Fermi Gamma-ray Space Telescope

Fermi Fridays - May

May is Cosmic Ray month! Cosmic Rays and Particle Acceleration
What exactly are cosmic rays, and where do they come from? Even though it was designed to detect gamma rays, Fermi has the ability to detect and measure the energies of cosmic rays that hit the satellite. Find out how Fermi scientists use this information to understand the source of these high-energy particles from space.
Fermi-LAT's Anti-Coincidence Detector is the first line of defense in distinguishing between cosmic rays and gamma-rays. But it can also be used to study these highly energetic paricles. Find out more about how the ACD detects and measures the various elements that make up the storm of cosmic rays hitting Fermi every second.
Surprisingly, at gamma-ray energies there are more cosmic-ray positrons than expected. Fermi LAT used the Earth as a precision magnet to separately measure electrons and positrons. Where do these extra positrons come from, perhaps dark matter?
Art of the Sky: Cosmic Rays and Cakes!
Cosmic rays have served as a source of inspiration for animators and confectioners alike. Take a look at some of the cosmic ray and ACD inspired creations from the past ten years.