At http://phys.org/print268989752.html … a meteoroid seen over the UK on September 21st 2012 (there is a short video film) which was very bright for just 40 to 60 seconds, has been analysed by a satellite tracker following a bit of speculation. The idea was mooted that it was a piece of space junk but this was quickly rejected. It was then said to be a piece of an Aten class asteroid which have an orbit that often crosses the orbit of the Earth. However, another analysis came up with the idea the object skipped like a stone in and out of the Earth's atmosphere (appearing as another meteor over Quebec a few hours later than it was seen in northern Europe). Further analysis now suggests it is not possible that the space rock could have boomeranged around the world to be seen 2 and half hours later over Canada – so there were two objects. Or were there?
George Howard at Cosmic Tusk has the same fireball incident posted up at his web site. He also has a paper that goes back to a conference in 1949 – see http://cosmictusk.com/unclassified-dr-edward-teller-and-the-anomalous-na… … which occurred at the time the UFO scare had got up and running – and green fireballs were a thing of mystery. The conference was held at the Los Alamos laboratory in New Mexico and at that time green fireballs had been seen recently. The debate covers noise (a whirring or whining sound associated with meteor observations as a result of electro-maghnetic effects, it was thought) and bouncing meteorites are also part of the transcript. The green colour, may, it was suggested, be due to the composition of the upper atmosphere.