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 Atoms As Big As Mountains — Neutron Stars Explained NASA Just Revealed There Could Be Life On Saturn’s Moon, Enceladus The Secret of the Dark Side of the Moon Could We Hide The Earth? Researchers Are Pretty Sure They’ve Found A New Planet In Our Solar System Watch SpaceX’s Emergency Pad Abort Test