'There's life out there'

Kevin Hand, a Nasa scientist, may not believe in fairytales but he does have a thing for Goldilocks.

This is not the girl with pigtails but the Goldilocks Zone, that habitable band found around a star that is seen to be neither too cold nor too hot but just right to support life.

Now there is a new Goldilocks in town, and it is here that Hand is searching for extraterrestrial life across the universe.

The old Goldilocks zone - slap bang where Earth is situated - is about the right distance from stars. But now scientists believe other variables like tidal flexing - caused by the gravitational pull of planets - and geothermal energy expands this habitable zone.

One of these places is Jupiter's moon Europa, and Hand believes life is likely to be found there. He said this at the Palaeontological Society of Southern Africa's 18th biennial conference at Wits University on Friday.

"For the first time in our history we have the tools and technology to do this experiment and go out to these worlds," Hand said.

Europa is covered in thick ice but deep beneath is believed to be an ocean, kept liquid by the gravitational force of Jupiter.

In that ocean might just be life, but the problem, he said, is how to get there.

Nasa is planning a mission to Europa in 2022 that will probably map the surface of the moon. But the mission to find life there might lift off only in 2040.

Once on the surface, Hand said, the lander would have to drill through maybe as much as 15km of ice. Below the ice is believed to be a 100km-deep ocean.

"The submersibles we have today would do fine in exploring Europa, the only problem is getting them there," he said.

What will those submersibles (small vehicles designed to operate underwater) find?

There might be organisms huddled around the ocean's hydrothermal vents, which spew out geothermal heated water. Microbial life, or even more complex life forms. There is even the possibility of the existence of intelligent life, although what it will look like is hard to imagine.

Though a mission on Europa is decades away, Hand is optimistic that in a few years we will be seeing life somewhere in the universe. Finding such life might be as simple as the Mars Rover turning a corner and finding a fossil on the Martian landscape. "I think in the next 20 years we will find out if we are not alone in the universe."