I think it's jumping the gun to presume it might be anything alien related, unless it was seen to hover, deviate from a straight course, or
significantly speed up/slow down. Occam's razor...
From reading the page on Wiki about green fireballs, it does sound as though many of the reports of "unusual" green fireballs are perhaps slight
over-reactions from people who have not seen many fireballs before. Fragmentation and fireballs that explode are not odd behavior, although some luck
and/or persistence is needed to see such an event. There were only perhaps one or two reports that may have been true UFO's from what I could see.
It's important to keep in mind, that this whole class of objects can play tricks on the eyes, especially on those who have little or no experience
with them. See this link (which I've posted on a few occasions before on this forum) if you have not already:
If you are considering looking for a meteorite/debris, you should first check for indications that it survived long enough to reach the ground,
otherwise it's just a waste of time. One sure way to tell if it did, is if any sonic booms were heard (assuming it's a meteorite/space junk, and not
something "alien"). If they were reported, there may be chance of finding something, but this is usually easier said than done...
If only one person saw it, then you are out of luck, since to pin down a possible landing site requires triangulation. Even if you can find a few
people that saw the event, the quality of the information they give you may not be good enough to define a trajectory and reasonably small landing
site. I'm sure there is software that can work out a potential landing site from the data you collect, taking into account wind direction/strength
during the dark flight stage of the objects' fall to the ground.
Then there is the question of terrain - many end up in the sea, and a good proportion of those that do not will be forever lost in difficult terrain
Ideally, you want photographs/video of the event taken from two separate sites 100-150KM apart.
If it's just crashed/fallen objects you are after in general, it may be better to find some volunteers and head for your nearest salt flat/tundra/ice
pack/other extremely flat and baron area.
Just in case any of you are fortunate enough to catch an event like this in the future, there are a few things you should remember to do, if you want
to provide the best possible information and increase the chance of finding anything that may have survived:
1. On it's appearance, note it's start position in relation to the stars and/or fixed terrestrial landmarks on the horizon, and start counting in
seconds up till it disappears from view. Note this time and the end point of the trail like you did for the start.
2. If you have a watch, look at it now and note the time to the nearest second. Check your watch against an accurate clock later to see if it's off
at all, and if it is, take this into account when submitting data.
3. Keep listening for sonic booms for another 5 minutes, and note the time if you hear any.
4. After this you should note things like brightness, color, presence of a persistent train etc... write it down then and there if you can.