Humans are so anthropocentric though, and so inclined to perceive only what they expect (cuddly ETs or scary monsters), they're unlikely to recognise any life forms that don't fit the conceptual identikit.
However, if there is life on the red planet - average temperature a chilly minus -80C, but with two moons which would be well worth seeing - it had better watch out, because Nasa and others are already planning to transport humans there and we all know what happened last time great nations sent voyagers into the unknown. They "discovered" America, Australia and New Zealand despite pre-existing occupants. Then they slaughtered locals, took their land, destroyed their cultures, introduced diseases and predators, exploited resources, and arrogantly reorganised and renamed everything as though it did not exist before their glorious landfall.
Maybe they didn't realise nowhere is far enough away to escape cause and effect? Nevertheless, consequences are ongoing - think Treaty settlements, kawanatanga, gorse, ticks and extinct huia.
Already, space cowboys blithely blundering into unknown skies have dumped a significant litter belt of about 6300 tonnes of junk into orbit around Earth since the first Sputnik in 1957 ... and they've only just begun.
Multiple scatterbrained projects have gained traction since - for instance, burying surplus Japanese corpses on the moon, installing mirrors in space to deflect the sun's rays from Earth to combat alleged global warming, firing nuclear waste at the sun (where they reckon it would not be noticed - yeah right) and most recently, experimentally blowing up a small moon of the asteroid Didymos.
When will we ever learn there are no actions without consequences; anywhere?
To me, sending humans to Mars sounds less like pure scientific inquiry, innate longing for like-minds in the cosmos, or adventure tourism, and more like cavalier greed; as in, OK so we've trashed one planet, let's move on.
Along with sexism, racism and other historic forms of arrogance, the outmoded idea that humans have dominion over everything as of right is foolish. We are stardust. Seeping Mars brine runs through our very veins.
The United Nations has a woeful record on Earth - a home planet wracked by war and toxic sludge for short-term profit - but it's the only (imperfect) global regulator we have.
The universe is yours and mine as much as it's anybody's so it's about time the UN, on our behalf, stepped up for a long-term universal future by setting up an Extra-Terrestrial Planning Council to impose strict resource and protocol consents for any further off-planet activity, before it's too late.
