Fermi Epicycles
May 5, 2012
The Fermi Gamma-ray Space Telescope orbits planet Earth every 95 minutes. It explores the cosmos and by design, it rocks to the north and then to the south on alternate orbits in order to survey the sky with its Large Area Telescope (LAT). Those are the paths of gamma-ray sources from the spacecraft’s perspective, as a result of multiple cycles. Credit: NASA, DOE, International Fermi LAT Collaboration
