Is there anywhere else in our solar system that could support life?

An imposing NASA probe due to lift off as Australia sleeps tonight might take the first real step toward finding out.

The Europa Clipper probe will lift off from Cape Canaveral, Florida aboard a SpaceX Falcon Heavy rocket at 12:06pm on Monday local time, NASA said. That is 3:06am on Tuesday AEST, or 4:06am AEDT.

The five-and-a-half-year-long Clipper mission will allow the US space agency to uncover new details about the Jupiter-orbiting moon Europa — which scientists believe could hold an ocean of liquid water beneath its icy surface.

"Europa is one of the most promising places to look for life beyond Earth," NASA official Gina DiBraccio said at a news conference last month.

The mission will not look directly for signs of life but will instead look to answer the question: Does Europa contain the ingredients that would allow it to thrive?

If it does, another mission would then have to make the journey to try and detect it.

"It's a chance for us to explore not a world that might have been habitable billions of years ago," Europa Clipper program scientist Curt Niebur told reporters last month, "but a world that might be habitable today, right now."

Largest NASA probe for planetary exploration

Europa has been known to scientists since 1610 and was first photographed by Voyager probes in 1979.

The images revealed mysterious reddish lines crisscrossing the moon's surface.

The next probe to reach Jupiter's icy moon was NASA's Galileo probe in the 1990s, which found it was highly likely that the moon was home to an ocean.

This time, the Europa Clipper probe will carry a host of sophisticated instruments, including cameras, a spectrograph, radar and a magnetometer to measure its magnetic forces.

The probe is the largest ever designed by NASA for interplanetary exploration.

It is 30 metres wide when its immense solar panels — designed to capture the weak light that reaches Jupiter — are fully extended.

Europa arrival expected April 2030

The probe will travel 2.9 billion kilometres on its journey to Jupiter, with arrival expected in April 2030.

The main mission will then last another four years.

The probe will make 49 close flybys over Europa, coming as close as 25 kilometres above the surface.

It will be subjected to intense radiation — the equivalent of several million chest X-rays on each pass.

The mission will look to determine the structure and composition of Europa's icy surface, its depth and even the salinity of its ocean, as well as the way the two interact — to find out, for example, if water rises to the surface in places.

The aim is to understand whether Europa is home to the three necessary ingredients for life: water, energy and certain chemical compounds.

Deputy project scientist Bonnie Buratti explained that if the moon fostered these conditions, life could be found in the ocean in the form of primitive bacteria.

But the bacteria would likely be too deep for the Europa Clipper to see.

What if the moon is desolate?

Some 4,000 people have been working on the $US5.2 billion ($7.72 billion) mission for around a decade.

NASA says the investment is justified by the importance of the data that will be collected.

But what if Europa is not habitable after all?

"That also opens up a whole wealth of questions: Why did we think this? And why is it not there?" Nikki Fox, an associate administrator at NASA, said.

If our solar system turns out to be home to two habitable worlds (Europa and Earth), "think of what that means when you extend that result to the billions and billions of other solar systems in this galaxy," Dr Niebur said.

The Europa Clipper will operate at the same time as the European Space Agency's (ESA) Juice probe, which will study two other moons of Jupiter — Ganymede and Callisto.

AFP/ABC