The study team, consisting of lead author & PhD student Eriita Jones, Planetary Science institute fellow Dr Charley Lineweaver, and Jonathan D Clarke of the Mars Society Australia found that, based on the pressure and temperature levels at which life could thrive on planet Earth, there is plenty of opportunity for life to do the same in the Martian sub-surface.
The traditional problems with supposing life on Mars are usually to do with water. Mars's relative lack of atmosphere, and hence pressure, means that any surface water would almost instantly vaporise and leave the planet's surface. If we work on the assumption that life requires, at some stage, water to survive (and all our terrestrial experience so far tells us this is so), then we need to dig a little deeper to get to a point where the pressure and temperature are both just right.
Dr Lineweaver told PopSci.com.au that, using data taken over the years by various other researchers, his team was able to work out the rate at which pressure and temperature increase as you descend.
"Based on that increase in pressure, and the temperature range at which we know life exists on Earth, we have found regions on Mars where you have the right temperatures and the right pressures to have liquid water there," he said.
"Now that doesn't mean it's inhabited, what we have found is the type of water in which life on earth would be happy".
Their findings, published today in the Astrobiology Journal, showed that based on these models, 3.2 per cent of the total volume of Mars was capable of supporting some kind of terrestrial-like life, at least on the criteria of pressure and temperature. Life is found in only about 1 per cent of Earth's total volume.
"Essentially, we're calibrating life by what it's done on Earth, and then we're just superimposing that on Mars, by saying 'Well, is the water, the temperature and pressure of that environment compatible with life we know of on earth?'
"The answer is yes, there are large regions of Mars where terrestrial microbes would be fine."
Of course, the difficulty is that this habitable surface is sub-surface, so Dr Linesweaver says if we were to look at Mars with our Earth-life goggles on, the largest organism we could resonably expect to find would be perhaps a worm.
The intrigue of the research, according to Dr Lineweaver, is not simply in what we could find on Mars. It's also in what we could take there.
"This analysis isn't just valid for a potential bioshpere on Mars, it's also valid for our microrganisms," he said. "Suppose you have a mission to Mars - we're going to take bacteria with us. Then we have another mission to Mars, and then over the next 100 years or so we have all kinds of microbes on Mars.
"Most of the bacteria die because it didn't grow in that environment - it hasn't adapted to it - but there will be some fraction that gets down into the surface of Mars and will possibly find energy sources."
The lower pressures and temperatures would also allow organisms to survive much deeper in the Martian crust, with conditions allowing for a hot biosphere reaching down to about 30 km, compared to Earth's five.
The proof however, is ultimately in the pudding. The current set of rovers, such as Opportunity, and the recently launched Curiosity, lack the ability to dig down any further than perhaps 20 centimetres of depth. Dr Lineweaver would like to see something that can go a little further than that.
"I think the next generation of Rover, partly motivated by the kind of work that was published today, will be moved to put on some kind of extra equipment," he said. "Maybe a shovel or even a drill that can go down, oh, half a metre, or a metre. I think that's where we're predicting things will get interesting. Or rather, more interesting."
So while the research was never designed to itself find a thriving alien ecosystem, the reality is it might be a step along a series of such movements that might, one day, do exactly that.
"I think it's important to note, "said Dr Lineweaver, "that the search for life elsewhere is one of the most profound things we can ask, and science progresses incrementally.
"I think this is some incremental progress towards trying to figure out whether life is or could be on other planets in our solar system, but also elsewhere in the universe."