Watch out for Comet Ison

Excitement is mounting among star-gazers all around the world, as what could be this year's big interplanetary event comes ever closer.

Comet Ison, or Comet C/2012 S1 to its friends, or Comet Nevski–Novichonok to its Russian friends, was hatched in the mysterious and distant Oort Cloud, and is currently hurtling towards the centre of the solar system.

Comet Ison, yesterday. Or possibly the day before

It will reach its closest point to the sun on November 28, zipping round behind and heading back outwards again for a close encounter with Earth some time on Boxing Day.

It's already visible from the UK if you have a good pair of binoculars and know where to look. It's a bit fuzzy, and has a slightly greenish tinge. But the big question is, will we get to see it with the naked eye?

Will it be as bright as the Great Comet of 1843, which had a stupendously long tail; or as dramatic as the equally Great Comet of 1882, which broke up into little bits and had a backward-pointing "anti-tail"; or as attention-seeking as the no less Great Comet of 1744, which was a proper show-off and boasted six separate tails?

Well, it all depends on who you believe.

If you take certain over-excitable newspaper columnists at their word, Comet Ison will be 15 times brighter than the moon and visible in broad daylight, will cast double shadows and will shine in through your bedroom window at night, keeping you and yours awake for the next three months.

Too flashy for its own good: the Great Comet of 1744

If you're of a more sceptical disposition, you'll more probably be of the opinion that it will be visible in the night sky but won't be as exciting as all that.

And if you're a complete and utter killjoy, you may well decide that Ison is fated to boil up as it goes round behind the sun and won't be here for Christmas.

The fact is, in the immortal words of Sir Patrick Moore, "we just don't know". But it's certainly something to look forward to.

There was a time, of course, when superstitious people thought that comets brought wars, plagues, famines, natural disasters, revolutions and the overthrow of governments in their wake.

In these days of rationalism, we're perfectly capable of organising most of those for ourselves without the help of an extraterrestrial chunk of ice.

But surely it's no coincidence that the papers right now are full of stories of mutant super-rats, of false widow spiders lurking under lavatory seats and leaping out to bite innocent bottoms, and of ghastly orange Spanish mega-slugs that threaten our native British gastropods?

(Mind you, if the Spanish slugs eat up the broccoli before Mrs D has a change to cook it, the can't be all bad, can they?)

Until Comet Ison fades back into the firmament next January, things can only get crazier.