Actually its a space parking token ...any alien will tell you to park your star ship in the grid at old town you need a token....you don't want an inter galactic ticket. And remember to be careful as old town is a crazy place....watch out someone dont tab you with the inter- galactic laxative ....it will get you back to mars....after that you'll be p--ping on the stars! klingons nasty!
The most common non-quarter I seem to find is Panamanian quarter Balboa. I think I have found five or six of them this year.