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 Astronomers discovered an ‘Interstellar’ black hole Asteroid Mining Mission Revealed by Planetary Resources, Inc. Peek Inside NASA’s Orion Spacecraft Does Earth Have A Second Moon? NASA’s On Course To Take Pluto’s Best Photo Ever Water-Extracting Device Headed To Mars In 2018