Several celestial bodies other than Mars pique the interest of astrobiologists.
Europa: The Jupiter moon apparently has a deep subsurface ocean and is a likely site of future robotic exploration.
Enceladus: In 2005, this small moon of Saturn was found to have ice geysers erupting from what is likely a liquid source beneath the icy crust.
Titan: Saturn's largest moon has an atmosphere thick with hydrocarbons and conceivably could have life forms with biochemistry different from what we see on Earth. “We call that ‘weird life' because it doesn't conform to anything we know,” said Jim Green, director of the planetary sciences division at NASA headquarters.
Others: “Weird life has no bounds,” Green said. “There might be weird life in a variety of places in our solar system. There may even be life under the ground in Venus.”