The Swift Planet

12345678910111213
Across
  1. 1. Spell out the time of one rotation in earth days
  2. 5. Mercury's takes the least time of any planet.
  3. 6. The planet closest to the sun.
  4. 8. NASA mission that orbited Mercury from 2011-2015
  5. 11. The primary metal making up its core.
  6. 12. Its position when planets are in order from the Sun.
  7. 13. The surface is heavily marked by this bowl-like feature.
Down
  1. 2. 88 earth days makes up one of these on this planet.
  2. 3. Mercury's lack of this causes extreme temperature swings.
  3. 4. NASA's first probe to visit Mercury in the 1970s.
  4. 7. Its diameter when compared to the other planets.
  5. 9. The extremely thin, tenuous outer layer of this planet.
  6. 10. This side of the planet can reach 800 degrees Fahrenheit.