Age: 4.6bn years old.

Appearance: Slightly different to its appearance last week.

You know, I thought that too. Has it had its hair done? No, not that, you idiot. Between you and me I think it might look a little more, well ... planet-y than usual.

Surely that can’t be the case. We’ve been through this before, remember? I know, I know. Pluto had been a planet since its discovery in 1930, only to be unceremoniously relegated to dwarf planet status by the International Astronomical Union in 2006. And yet ...

And yet what? And yet the Harvard-Smithsonian Centre for Astrophysicists is lobbying hard for Pluto to become a planet again.

Why? We’ve just had all the textbooks reprinted. It’s all about the definition. According to the Harvard-Smithsonian news blog, even if Pluto is a dwarf planet, we should still treat it as a planet because: “A dwarf fruit tree is still a small fruit tree, and a dwarf hamster is still a small hamster.” The centre had a debate, and then there was a vote, and the result was overwhelmingly in favour of Pluto’s reinstatement as a planet.

What happens if we do let Pluto back in? Well, there’s a chance that other distant trans-Neptunian objects – such as Triton or Eris or 50000 Quaoar or 90377 Sedna – could also qualify for official planetary status.

But this is madness! The floodgates will open! We’ll never be able to turn back the tide of shifty-looking would-be planets looking to get an unjustified cut of our solar system! All right, Farage, rein it in.

Fine. But does any of this actually matter? If you’re a member of the International Astronomical Union or the Harvard-Smithsonian Centre for Astrophysicists – basically the Sharks and the Jets of the planetary-definition game – then yes.

And what does Pluto make of all this? Pluto is a massive clump of rock and ice trapped in a lonely silent orbit through the dark recesses of space several billion miles away from Earth. As such, it could not be reached for comment.

Do say: “Welcome back to the solar system, Pluto. We’ve missed you.”

Don’t say: “Now get out. We’ve changed our minds again.”