Scientists Think Mars Once Had Water. So What Happened to It? Mars may have had a core similar to Earth’s. It’s possible that when it diminished, the planet’s water went with it. Facebook Prev Article Next Article Space Checkout these cool gadgets... Related Posts An Astronaut’s View of Earth with Col. Chris Hadfield Is the Sun Being Tilted By Large Unknown Object? The Strange Case of the Himiko Blob NASA Might Send a Helicopter to Mars NASA’s Gold Box Will Make Oxygen on Mars Why NASA’s Proposed Mission To Europa Is A Big Deal