NASA is planning a mission to Jupiter's watery moon Europa, a place scientists believe is the Solar System's best bet to host alien life, at least a decade from now, officials announced Tuesday.

The White House's 2015 federal budget request set aside $15 million for the space agency to start planning some kind of mission to Europa, CBS News reported.  The moon harbors a layer of liquid water beneath its surface that could potentially support life.

Although no details have been decided yet, NASA Chief Financial Officer Elizabeth Robinson told reporters Tuesday that it would be launched in the mid-2020s.

"Europa is a very challenging mission operating in a really high radiation environment, and [there's a lot] to do to prepare for it," Robinson said, according to Space.com. "We're looking for a launch some time in the mid-2020s."

When NASA sent spacecraft Galileo to Jupiter in 1989, it took the device six years to get to the fifth planet from the sun, CBS News.

Robinson said the $15 million would fund very early "pre-formulation" work for a potential Europa mission.  The amount represents a small fraction of the $17.5 billion allocated to the space agency in the 2015 request.

"I know people have asked about the total size [of the possible mission], and we're frankly just not sure at this point," she said.

She said the major goal of the mission would be searching for life in the layer of liquid water under the ice-covered surface, according to CBS News.

Robinson added that agency officials will reach out to the scientific community to help map out the mission.

Avi Loeb, an astronomer at Harvard University, told CBS News tha going to Europa would be more exciting than exploring Mars.

"There might be fish under the ice," he said.