Originally posted by netwarrior
The one I saw was blue/green. No trail, though. It was moving way too slowly for that.
Too slow to be a meteor
It's likely what you saw was a bit of space-junk reentering the atmosphere (as I said in your thread), but the slowest meteors can also be very slow,
and hard to tell from space-junk based on speed alone.
Re-reading your thread again, I noticed that you also stated that you thought the object was low in altitude, and you also estimated the size and
apparent velocity. The trouble with estimates of the type you made is that there are no reference points or cues which can give you clues as to what
the true size/velocity/distance is.
Our brains are wired up in a way that is geared to everyday life on the ground, where there tend to be more visual cues which enable our brains to
work out distance/velocity/size with a fair degree of accuracy. However, without those cues, our brains have to make assumptions, and these are based
on the assumption that what we are seeing is in a common every day situation (ie on the ground), which is not
the case, and consequently, our
estimations are usually off by a long way.
People seeing bright meteors and fireballs are especially vulnerable to this effect/optical-illusion, since our brains use brightness as a cue for the
size of an object - a bright object/light is perceived as being close, where as a dim object/light is perceived as being far off. BUT, fireballs can
be exceptionally bright, even though they are high up in the atmosphere and a long way off. The brightness also gives us cues as to the size of an
object, since the brighter it is, the larger it looks, but this is also misleading when it comes to meteors.
Also, when we see something that appears to be "only just above the horizon", this is also quite misleading, since in the case of a meteor, it can
be high up in the atmosphere, but if you are a few hundred miles away from it, it will look like it is close to the ground because Earth's surface is
curved and not flat. For example, if you have ever watched the Moon rise above the horizon, you know that it is many, many Km away, but it still looks
as if it's hovering just above the horizon.
All of the above contributes to people saying things like "I saw it fall just over the hill" or "it came down just beyond those trees", but we
know this can not be true since we know that even large meteoroids are usually slowed down to the point
where they are no longer luminous below 30 Km altitude in the vast majority of cases
Since we are all hard-wired in the same way, we see reports like this with virtually every large fireball that is seen by many people over a wide
area. If it was the case that people were actually seeing fireballs close to the ground, then you would expect them to be heard since to be luminous a
meteor has to be traveling much faster than the speed of sound, and any object exceeding the speed of sound will produce a sonic boom/booms. You can
usually tell if you are close to a meteorite fall-site since booms would likely be felt/heard in the surrounding area.