NASA researchers believe they’ve found strong evidence that there could be underground life on Mars, huddled around pockets of liquid water. They haven’t found the life directly, but instead have discovered a unique methane signature that matches similar environments here on Earth, such as subsurface areas around Rio Tinto, a red-stained river in Spain. In order to get confirmation, NASA would need to send a spacecraft to Mars capable of drilling into the ground – unfortunately, none are planned currently.