greetings, today i post this. it is one of the best posts ive seen in a while.
dealing with my all time favorite topic - UFOs:
Strange UFO Coin from 1680 Puzzles the Experts
Thought I would drag this one up mostly because I found a great copy of the coin on a numismatic page that shows both sides...

Looking around the web there are basically three opinions on what it represents....

1) a UFO, depicting something seen in the 1600's (seems there are several stories of a flap in that era)
2) the 'Flying Shield' of Jupiter
3) a representation of Ezekiel's Wheel..

Here is the coin in question in high resolution
OPPORTVNVS ADEST translated as "It is here at an opportune time"
Here is the reverse side...

HÆC PER TE AVCTA COLAM translated as "Let this growth be pleasing for your heart"

Looks like a Tree of Life representation
Opinions?...
source:
http://www.abovetopsecret.com/forum/thread669572/pg1

~thank you 4 your interest here-xoxo!