Okay, a bit more detail on the locations of the little burning orbs. As I said last night, there may well be a rational explanation for this. And I can't tell you how painful it is to write those words; talk about deflated.
But let's record it all properly anyway.
So, Orb 1 I saw travelling from east to west along the A361 Avebury to Devizes road. I don't often go along this particular road (and would have missed the whole thing if the road to Marlborough hadn't been suddenly closed) so can't say precisely where I was when I saw the light in the sky, but it would have been a few miles outside Devizes, say roughly level with the village of Bishops Canning, let's say at SU039654 (51.388N, 1.946W). The object would have been roughly south of me, but it's very hard to say where and how far away (more on this below).
Orbs 2, 3 and 4 I can be much more precise about, as I know the road much better, the objects were much closer, and I had a range of hills in the middle distance to place them against. These I saw travelling from west to east along the A342 Devizes to Upavon road. Orb 2 I saw just west of the village of Chirton, at about SU072570 (51.312N, 1.898W). It was to the south to south-west of me above an escarpment called Chirton Bottom, likewise Orbs 3 and 4, which I saw just east of Chirton, from about SU080568 (51.310N, 1.887W). The place I stopped and jumped out of the car would, I think, have been the turn-off to a village called Marden, at SU085567 (51.309N, 1.880W). I might just have been one turning further on, but I can clarify that in daylight at a later date if needs be.
Anyway, this is the critical bit. I saw 1 some way away to the south when travelling east-west, and 2, 3 and 4 closer to the south when travelling west-east, parallel to the previous route (having essentially gone into and then out of Devizes in the opposite direction). It's much harder for me to be precise about where 1 was, but I'm now thinking it was probably in the same sort of area as 2, 3 and 4.
As I mentioned last night, Chirton Bottom is at the outer edge of the Larkhill artillery range. Larkhill is an army camp and headquarters of the Royal Artillery, in the vicinity of Stonehenge, and I often pass through there on my way between Hampshire and Wiltshire (should have made the connection to Larkhill at the time, didn't realise I was so close to it).
There must be a very strong possibility, therefore, that what I saw the other night was merely a military exercise, which would accord with the percussive thump I heard from behind the hill. I'd also have to concede that the beam of light I saw coming from Orb 4 was no such thing, but was rather the light from whatever it was merely illuminating the ground beneath it.
But I will take a walk over there soon in daylight, as much as anything because it's a lovely looking part of the Vale of Pewsey that I don't know in the way that I know the eastern parts of the vale. Most of the artillery range, and all the area around Chirton Bottom is publicly accessible land, served by footpaths, like most such ranges (the part around the army camp itself is obviously private, but many army ranges in the UK are open to the public except on days when they're firing, when they put red flags out).
So, sadly, possibly all quite mundane.
Except, just a couple of anomolies.
1. Whilst Orbs 2, 3 and 4 could possibly be seen as having the motion and trajectory of artillery shells, Orb 1 was either stationary or moving sideways (can't really say for sure, because everything was so dark and indistinct, and I was moving at the same time - the others were much easier to judge, because I had a backdrop of hills to visually contextualise them against), and that would not accord with a shell.
2. Orbs 2, 3 and 4 appeared very close above Chirton Bottom, which as I explained above is right at the outer extremity of the firing range, in what is basically a buffer zone, in that no shell would be expected to get that far, but for obvious reasons the army allow for one doing so, just in case, so it's a little odd that they seemed so close to the hill.
Worth keeping an open mind about, but likely nothing to get too excited about, so sorry for doing just that yesterday! But at the time, it really was quite something.