Last night (7 march) was quite clear and all stars brighter looking than normal. it was mild and i stood in my back yard with my brother as i had a cigarette and we were looking up at the bright stars and chatting. there was fast moving patchy cloud. my brother is short sighted and does not wear glasses or lenses, but he could see stars and we were talking about how they seemed brighter than normal. we were looking up approximately north west at a constellation, when a strangely kind of blurred looking and much fainter light caught my eye, which to be very high - probably in outer space. it was moving very fast and in a straight line - and changed direction instantly with no loss of speed. it did this repeatedly the whole time i could see it, like overlaying letter m, z, and v to give you an idea. i instantly pointed to it saying ‘what the heck is that??€™ to my brother, who was looking up but struggled to locate or see it for about 5-6 seconds as it zipped about. he finally did manage to locate it, though only very very faintly because of his short sighted vision. it zipped and darted so fast, changing direction less than every 1 second, after moving a distance of something like a 10cm straight path in the width of my vision. the whole sighting was around 10 or 12 seconds, long enough for me to be certain it was not some kind of perceptual distortion like those drifting dots your eyes can generate, and absolutely was not any kind of aircraft that i know about. the movement was way too fast and the direction changes too sudden for it to be a bird and it was clearly to me not an insect or really any other thing i could think of. the perculiar dimness of the light was striking, as was the odd blurryness of it. in contrast to the crystal sharp appearance of the bright stars on the black night sky backdrop it really stood out. after the 10 or 12 seconds the light appeared to just rapidly fade to nothing and was gone.