NASA scientists believe that one of Jupiter's moons is the most likely place in the universe beyond the Earth that could harbour life.Europa, the sixth closest moon to the planet, is far more likely to be habitable than desert-covered Mars which has been the focus of recent US exploration, they say.It's ocean, thin shelf of ice and the presence of oxidants on Europa make it far more likely to be home to a life form than the red planet.Now NASA says it has revised plans to explore Europa, coming up with a cheaper way of completing its mission.Robert Pappalardo, a planetary scientist at NASA's jet propulsion Laboratory (JPL) in Pasadena, California, told France 24: 'Europa is the most promising in terms of habitability.'It is the place we should be exploring now that we have a concept mission we think is the right one to get there for an affordable cost.'
Speaking at the American Association for the Advancement of Science (AAAS) annual conference, Mr Pappalardo said that a new $2 billion exploration project called Clipper would see NASA team up with physicists from the John Hopkins University in Maryland if it gets the go ahead.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.Mr Papparlardo says 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.But NASA announced late 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, the craft which has been exploring the surface of the planet since last August, at a cost of around $2.5 billion.The probe Juno is to arrive in the orbit of Jupiter in 2016, but after it is crashed a year later, the US will have no probe's in the outlying reachers of the solar system.
It could however, team up with the European Space Agency which plans to launch a mission to Jupiter in 2030.Europa was first examined by the Voyager mission in 1979 and by Galileo in the 1990s.As well as Europa, scientists believe that Encelade, a moon belonging to Saturn, could also be habitable.