A new NASA study hints that alien life may be closer to home than we thought.
For decades, Mars has been the subject of scientific study when it comes to finding extraterrestrials.
It's also been the focus for many in Hollywood, with countless TV shows and films produced hypothesising the existence of other life forms on the planet closest to Earth.
Putting Mars Attacks! and Pierce Brosnan's head on a dog's body aside, though, and it seems like we're heading back in a direction where little green men could be a real thing.
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The big difference, in reality, is that they are likely to not be green, and will in fact be very, very small.
A new study by the Jet Propulsion Laboratory (JPL) at NASA has looked in to whether we should be once again actively investigating if there is life on Mars.
And according to the paper’s lead author, Aditya Khuller, the answer is 100 percent yes. Just not on its surface.
He says: "If we’re trying to find life anywhere in the universe today, Martian ice exposures are probably one of the most accessible places we should be looking."
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Mars has for some time known to be home to water, and ot's believed to once have been full of the stuff.
On the planet, it manifests itself in to ice, of which there are two kinds: frozen water and frozen carbon dioxide.
For their paper, published in Nature Communications Earth & Environment, Khuller and colleagues looked at water ice, large amounts of which formed from snow mixed with dust that fell on the surface during a series of Martian ice ages in the past million years.
That ancient snow has since solidified into ice, still peppered with specks of dust - dust that is dark in colour and can absorb more sunlight.
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The theory here is that this could potentially warm up the ice, causing it to melt up to a few feet below the surface.
From that, ancient life in the form of microbes could be surviving, and maybe even thriving, under the frozen water ice on Mars' surface, where photosynthesis could be happening.
Pools of water similar to those that could be on Mars exist on Earth and are full of life, from fungi to algae and microscopic cyanobacteria.
The concept of whether ice can actually melt on the Martian surface remains up for debate, due to a terrible thin and dry atmosphere that is not like Earth's.
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But, critically, the atmospheric effects that make melting difficult on the Martian surface wouldn’t apply below the surface of a dusty snowpack or glacier.
Co-author Phil Christensen, of Arizona State University in Tempe, said that ice melting from within is 'a common phenomenon on Earth'.
He said: "Dense snow and ice can melt from the inside out, letting in sunlight that warms it like a greenhouse, rather than melting from the top down."
The team now hope to re-create the dusty ice from Mars in a lab to study it under similar conditions to what you would find up on the Red Planet.
Tom Earnshaw