Learn why NASA scientists are so excited about all three of this year’s essay contest topics. All three of these moons are interesting to planetary scientists, because they have each been observed on only one side. What does the back of each of these moons look like? We don’t know! And neither does anyone else... yet.

Topic 1: Miranda, Moon of Uranus

Dr. Yackar Mauzole thinks that Uranus' moon Miranda is the best topic. Miranda, the fifth largest moon of Uranus, has only been explored so far by NASA’s Voyager 2 spacecraft in 1986. Its Frankenstein-like surface appears to be cobbled together from many types of rock and ice.

Additional Resources

Topic 2: Triton, Moon of Neptune

Dr. Sabah Bux thinks Neptune's moon Triton is the best topic. Triton, the largest moon of Neptune, has nitrogen ice on its surface and a core made of rock and metal. Triton is volcanically active, and it has a very thin nitrogen atmosphere. NASA’s Voyager 2 spacecraft flew by Triton in 1989.

Additional Resources

Topic 3: Charon, Moon of Pluto

Melissa Soriano thinks Pluto's moon Charon is the best topic. Charon is the largest moon of the dwarf planet, Pluto. The New Horizons spacecraft flew by Charon in July 2015.

Additional Resources

If you could send a robotic spacecraft to learn even more about Miranda, Triton, or Charon, which moon would you like to study further? What do you think we might find there?

All three of these moons conceal a mystery: What does the back of each moon look like? Flyby missions only reveal the side of the moon that’s visible by the camera on the passing spacecraft. Since each of these moons has only been visited once, we haven’t had a chance to see the back of these moons yet. If we could return to one of these moons with a robotic spacecraft, what do you think might be there? What do you hope we might find?

Related News