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 This Is How Astronauts Wash Their Hands In Space Top 10 Signs of Alien Life Why Doesn’t Earth Have Rings? Top 10 Weirdest Things Out in Space Hibernation Is Not Just for Bears but for Astronauts Too 5 Most Mysterious Signals from Space