Last week, the Deep End was dedicated to the grubby world of British politics, today we lift our eyes to heavens – and in particular to a newly discovered planet called Kepler-186f.

Writing for the Atlantic, Adrienne LaFrance provides a fascinating travel guide:

“Right now, 500 light years away from Earth, there’s a planet that looks a lot like our own. It is bathed in dim orangeish light, which at high noon is only as bright as the golden hour before sunset back home…

“It’s the first Earth-sized planet in the habitable zone of another star—the sweet spot between too-hot Mercury-like planets and too-cold Neptunes— and it is likely to give scientists their first real opportunity to seek life elsewhere in the universe…”

The true significance of Kepler-186f is that it provides the strongest confirmation yet that our galaxy – and, by extension, the known universe – contains vast numbers of Earth-like worlds.

If true, it poses what may be the greatest scientific puzzle of all time – which, last year, was the subject of a Ross Douthat column for the New York Times:

“If Earth-like planets are relatively common, as scientists increasingly believe, then where are all the Earth-like civilizations?

“This mystery is known as the Fermi paradox, after the physicist Enrico Fermi, who raised it at lunch with fellow scientists in 1950. He pointed out that our Sun is a relatively young star, and billions of other suns are billions of years older. If even a tiny fraction of those suns have planets like ours, and even a tiny fraction of those planets developed life, and even a tiny fraction of those life forms achieved human-level intelligence … well, the number of civilizations capable of interstellar communication and travel should be theoretically large enough to crowd our galaxy with signals, ships, artifacts.

“In which case, Fermi asked, Where is everybody?”

It’s a good question to which there are many bad answers. For instance, there are those who believe an alien civilisation has placed us in quarantine, somehow concealing themselves from us in the process. Well, one could hardly blame them – but the problem with this theory is that any extraterrestrial intelligence capable of such a feat would also be capable of manipulating everything that we have ever perceived as a species. The entire basis of human knowledge would therefore be suspect – so there’d be no point in arguing about this or anything else.

Other theories include the idea that space travel between solar systems is just too difficult or that civilisations inevitably destroy themselves (or find something more interesting to do) before achieving interstellar space travel. The objection here is that with the potential in time and space for so many different civilisations, it seems unlikely that they should all be subject to the same limitations. Indeed, the same objection applies to the quarantine theory discussed above – one set of aliens may see fit to stick us in special measures, but with so many civilisations to choose from, it’s inevitable at least one would wish to intervene in some visible way – or reveal their presence accidentally.

Douthat puts forward another explanation:

“Perhaps life and consciousness are rare enough, mysterious enough, impossible enough, that even multiplying Earth-like worlds a billion times over would not necessarily produce either one again.”

This is the most controversial theory of them all because, as Douthat notes, it “raises theological as well as scientific questions”:

“In one sense, it elevates humanity, restoring us to an almost pre-Copernican position in the cosmos.”

It’s an idea freighted with spiritual, moral and political significance.

The story of modernity is one in which humankind has been shifted from the centre of creation to its periphery – a naked ape, on an unremarkable planet, in a backwoods galaxy.

The perception that we have no special place in the universe is, one might suggest, the basis of contemporary liberalism. If, in the greater scheme of things, none of us matter very much except to ourselves, then each and every individual may as well put themselves at the centre of their own universe.

If, on the other hand, it turns out that we do have a unique place in all creation – and that our very existence is a miracle – well, that puts the matter in a very different light.