Everything is relative. I believe a physicist once even came up with a theory in this area. Relativity was the unspoken subject in The Planets (BBC Two), in part one of which Brian Cox supplied a potted biography of our (relatively) near neighbours. The universe has been around for 14 billion years, but Earth, he said, for only four billion of those. So we are, relatively speaking, galactic newbies.
I put that in my pipe and smoked it as Cox proceeded to explain a thing or two about Mercury, Venus and Mars, which we think of as being one thing but at one time were quite another. Mars, which Matt Damon found so fiendishly inhospitable in the 2015 film The Martian, once flowed with cascading rivers. It used to rain on Venus. Mercury is the really weird one. Owing to the loopy shape of its orbit, its temperature varies by 500 degrees Celsius and its day – get this – is twice as long as its year.
A big question for The Planets, though maybe not the biggest, for is one of outreach. Would it speak to those who, naming no names, seem to remember failing their physics O Level back in the day? On the whole, the answer is yes. Whenever I hear the word “quark” I tend to do a massive runner. But Cox spoke slowly and clearly and illustrated his points from a variety of spectacularly remote locations, with the result that only a couple of times did one’s brain turn to Venusian fog.