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 Here’s How We Could Reach Mars In Just 30 Minutes Glimpsing the Solar System’s Birth “World’s first battery-powered rocket” readied for launch Finding Earth’s Twin What Happens At The Edge Of The Universe? This 19-year-old can keep astronauts safe from space junk