First of all, balloons are much more eritrac in their movement at that altiitude, test it out for yourself if you'd like, I already have. Even use a cluster of shiny Happy Birthday' balloons, it doesn't reflect light the same way. Secondly, they would have to be extremely cultured material to be able to survive the pressure change at that altitude. But, who knows? Even if it was an ETI, would anyone really be surprised? Statistics say no.

First of all, balloons are much more eritrac in their movement at that altiitude, test it out for yourself if you'd like, I already have. Even use a cluster of shiny Happy Birthday' balloons, it doesn't reflect light the same way. Secondly, they would have to be extremely cultured material to be able to survive the pressure change at that altitude. But, who knows? Even if it was an ETI, would anyone really be surprised? Statistics say no.