Charon: Pluto’s Giant Companion Moon

  1. Charon is the largest of Pluto’s five moons, discovered in 1978.
  2. It’s so big compared to Pluto that some call the pair a double dwarf planet system.
  3. Charon is about half Pluto’s size, measuring 750 miles across.
  4. Unlike icy Pluto, Charon’s surface is darker and more rock-rich.
  5. A massive canyon system on Charon is longer and deeper than the Grand Canyon.
  6. The moon shows evidence of past cryovolcanism, with icy flows freezing on its surface.
  7. Charon is tidally locked with Pluto, always showing the same face.
  8. The reddish north pole, nicknamed Mordor Macula, is stained by gases escaping Pluto.
  9. Together, Pluto and Charon orbit a common center of gravity outside Pluto itself.
  10. NASA’s New Horizons mission in 2015 revealed Charon’s detailed landscapes for the first time.