If something from off of Earth is "extraterrestrial", what's something from off of Mars?

Earth is "terra". Mars is, well, Mars. Actually "ares", so something from off Mars is "extraarestrial". Well, searching Google for that found one other reference of somebody thinking the same way. And if you search "extramartial", you get a lot of hits but they aren't about Mars.

So, Opportunity might have found another extraarestrial object -- i.e., another meteorite.

Sure looks like it.