Jupiter's moon Europa is the most likely candidate in the Universe beyond the Earth that could harbour life, NASA scientists believe.
Researchers say Europa, the sixth closest moon to Jupiter, is far more likely to be habitable than even desert-covered Mars which has been the focus of recent exploration.
The presence of an ocean, a thin shelf of ice and oxidantson the surface of Europa make it far more likely to be home to a life form than the red planet, the 'Daily Mail' reported.
NASA says it has revised plans to explore Europa, coming up with a cheaper way of completing its mission.
"Europa is the most promising in terms of habitability," Robert Pappalardo, a planetary scientist at NASA's jet propulsion Laboratory (JPL) in Pasadena, California, told France 24.
Pappalardo said that a new USD 2 billion exploration project called Clipper would see NASA team up with physicists from the John Hopkins University if it gets the permission.
The mission follows the success of Cassini, a probe that closely explored Titan - a moon of Saturn. NASA will send a spacecraft into Jupiter's orbit and conduct a number of close flybys of Europa.
Papparlardo said that exploring Europa using the flyby method will allow scientists to explore the moon in its entirety.
Clipper could be launched by 2021 and would take a further three to six years to reach Europa, the report said.
However, NASA announced last year that there are currently no funds for the mission. Instead, it will send a new robot to Mars in 2020, similar to Curiosity.
Europa was first examined by the Voyager mission in 1979 and by Galileo in the 1990s. Scientists believe that Encelade, a moon belonging to Saturn, could also be habitable.