We've sent spiders to space[0] (honestly, it's like we _want_ a horror movie to play out). But who knows - maybe one day we'll get DNA from extraterrestrials.
i think terrestrial would mean earthly. from the latin root, terra, for earth. from space is extra-terrestrial. But then greek is geo, or gaio like gaia. but we dont call aliens super-gaians. I dont know where im going with this. Language is messy. English doesnt include every version of every root. We do have subterranian though. Superterranian?