Need scientific/government explanations of UFOs

I have an idea for the banner contest thingy, I don't know how good it will be, or even if I will finish it once I start (it just may not turn out to be good enough to post) but I need scientific/government explanations for UFOs.

For example:
ball lightning
electrical flashes
natural gases in the atmosphere
satellite debris
weather balloon

Anybody have any more? Thanks!

I saw mushrooms used once.

I posted about it in a thread here awhile back, complete with story.

Edit: No not mushroom hallucinations, actual mushrooms on the ground said to be the explanation of the UFO's.

[edit on 23-7-2005 by Dulcimer]

What comes to mind:

Meteors
Bolides
And an explanation that's based on earth activity (think earthquakes but smaller) causing magnetic displays in the sky.

birds
manmade secret aerial vehicles ( which I believe most UFOs are)
manmade aerial vehicles a.k.a. planes
flying chinese lanterns

blimps
The SkyShip *never heard anyone use it as explanation tho*

i dunno why...the skyship would be a perfect cover for UFOs
why didnt they use it?? to debunk others with?

They've used Venus many times, except venus doesnt accelerate or move in zig zags.

thats why they add the "they were on drugs" excuse

so they can explain how venus moves in zig zags and 90degree turns etc

* Ice crystals.

I think they mentioned it regarding the "Nasa STS-87 anomalies".

Temperature Inversions.

This was the explanation used during the 1952 wave.

oh, not aliens - what about the geomagnetic lights produced from stresses in rock

[edit on 24/7/05 by Strodyn]

-Swamp gas
-Solar eclipse
-Ball of lightning
-A gas plant on the sea (used to debunk the famous Mexico airforce tapes of UFO's)
-Meteors and comets of course
-Lightning
-Electromagnetic fields that influenced the brains of people so that they imagined things(also used to debunk ghosts)
-Garbage lid or something else thrown in the air
-The tape or photo was digitally altered
-Faulty radars
-All kinds of baloons or other exotic terrestial made flying objects
-The northern lights
-Sattelites
-Commersial or private airplanes
-A building on fire far away reflected in the low altitude clouds
-Ground lasers reflected on the clouds
-Light from cars replected on the clouds or light from cars of a hill
-Flares dropped from a military airplanes (debunked the Phoenix lights)

And if none of these fit, the debunkers just say "Unexplained atmosferic fenomenon", which is a scientists way of saying "I give up explaining it, but you will never get me to say it's a UFO!".