Some people have trouble accepting the existence of cosmic aliens. They shouldn't. We earthlings are certificated members of the club.
Wonky conspiracy theories aside, to date exactly one dozen homo sapiens have shuffled their moon boots around in the Moon's dusty surface.
Six of those also managed some lunar automotive jaunting, and one even a spot of moon golf. We like to spread our addictions around.
To any unseen inhabitants already calling the Moon home, our gallivanting astronauts were real McCoy cosmic aliens, who'd travelled far to invade their space in tin capsules the natives undoubtedly called UFOs, or the local equivalent.
Sceptics ask, where's the evidence of existing moon dwellers?
Firstly, it's not necessary for there to be actual inhabitants for extra-terrestrial visitors to still be categorised as aliens. Secondly, as any pulp science fiction tale can tell you, resident locals could well exist behind a parallel universe veil that crude earthling eyes are incapable of penetrating.
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For all we know, an entire population of moonlings were avidly watching our first bumbling but amusing baby steps on a celestial body other than Earth, all sniggering behind the equivalent of a vast one-way mirror as we played at being Buck Rogers.
The re-runs of the TV comedy series they no doubt subsequently made based on our Apollo programme moon trips are probably still keeping the locals in fits.
So, no argument we're already bona fide aliens ourselves. So what's the problem in accepting there could well be plenty of others out there?
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Countless others. Fully paid-up members of the League of Aliens. Then again, you only get to be aliens if you travel. Other planetary populations may exist, but sensibly stay home, mind their own business and carbon footprint, and take care of their knitting.
Perspective is important. As George Orwell observed, in so-called communist societies supposedly exemplifying egalitarianism, invariably a select bunch ended up being definitely more equal than others.
Likewise, even though post-Apollo earthlings are now certified aliens, nevertheless some seem a tad more alien than others. Some, way more.
There are many fully convinced that if only one could find the concealed switch, the hinged collapsed-souffle scalp of the 45th President of the United States of America would lift to reveal a control console of sundry levers and digital read-outs all controlled by a fiendish cosmic overlord.
But should fellow beings be abroad in the vastness of the galaxies, for earthlings to boldly go where no man has gone before with their split infinitives must still be a major concern for them.
The thought of Richard Branson with his Viking mane and Neanderthal teeth suddenly dropping in for lunch is sobering enough.
Even more sobering, though, is the fact that earthlings now aspire to shoot for more than the Moon, and may one day reach Mars, or wherever, lugging suitcases full of our seriously bad habits.
No doubt potential hosts are already frantically strategising to thwart just such possible alien-earthling visitations.
Other cosmic denizens must have watched in dismay as homo sapiens slowly evolved over multiple millennia – along with the geology and ecology of planet Earth itself.
As various civilisations rose and fell, no doubt the observers rationalised the ongoing cavalcade of butchery, barbarism and brutality as unpleasant but necessary growing pains of an adolescent planet, albeit punctuated by promising occasional peaceability.
But their foo-foo valves must have totally popped when they saw how we started to industrially defecate in our own nest once we had the technological capacity to do so.
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What sort of species – they asked each other – would take such abundant natural riches, generously allocated to so many for so little, and then trash the whole kit and caboodle upon which life depends all to create a military-industrial plasticised polluted consumerist train-wreck?
Be scared. Malevolent aliens are already here. They're us.
Any other cosmic communities may well regard us as the rellies from hell.