It looks vaguely familiar, but I can't place it..
FWIW - My thought process:
1) Almost too ugly to be a car hubcap (even though many are ugly!)
2) If a car, then more likely to be one of the big three, back in the day.
But, you can't rule out AMC cars, because they defined ugly.
3) Likely mid-50's to mid-60's, when the space race and rockets were all the rage
4) Possibly for a car with a space-sounding name, like the Comet, Starfire, or even brand, Mercury, etc...
5) Probably too big to be a pedal car hubcap, etc..