Of course Bruce was aware that aliens existed. Hell they had fought them in New York and Thor was considered to be an alien, but this ship....it was on a whole different level. It felt more real than any of those other things. Bruce couldn't have helped the gaping jaw, wide-eyed look he was giving.
That was until Wash so gracefully pointed it out. Bruce closed his mouth and looked over at the pilot after wrinkling his nose a bit in response.
Bruce nodded when Wash offered to show him the inside, "Sure, id love to see it." He stepped forward and pressed a palm against the metallic outside, looking it over, "So what do you call this thing?" He couldn't remember Wash ever telling him the name, but he supposed it could've come up in conversation. Having a lot on your plate mad wit hard to remember fine details that one could usually remember without problem.
"You should recruit Tony to help you fix it up. He's great with mechanics." Bruce was pretty good too, but he was much better at radiation and physics more than tech and mechanics.