Twitter just exploded with reports, pictures, and videos of an extremely bright fireball moving over the northern part of the UK at around 22:00 UTC. I've seen tweets from folks in Ireland, Manchester, and more. It was traveling east-to-west, and broke up into many pieces as it fell. No reports of it hitting the ground yet, though some pieces may fall all the way down.
Here's the best video I've seen so far:
Other videos are not as clear but do show the same object (note the positions of the individual pieces as they move). Here's one from Ross Shankland:
and another by Rowan Kanagarajah:
Here's a picture from @Mr_Danger:
It's too early to tell, but this may be a actual meteor - that is, a rock burning up - or it may be space debris, a piece of a satellite re-entering. Meteors tend to move quickly, zipping across the sky in a few seconds; they are moving at 20 - 50 kilometers per second and sometimes more. Orbital debris is slower, moving at less than 10 km/sec. Both have been known to break up (like the Peekskill meteor did, or the re-entry of an ATV in 2011).
I'll update this as I get more info. But I have to say how jealous I am of everyone who saw this! And if you did witness it, you should file a report with the IMO, so they can collect all the info - it may help lead to finding meteorites, pieces that have made it all the way down to the ground!
My thanks to everyone who tweeted links to the pictures and videos.