Curiosity's discovery that Mars was once habitable has brought up again the implicattions for humans of life on Mars. Most scientists assume that if the life is simple microbes, most people won't have a problem with assimilating the find. Indeed, there's probably very little chance anything more complex than a microbe will be found there.
However, if we find a fully articulated, beautifully preserved fossil of Something. all bets as to the human reaction are off.