NASA scientists announced that Mars could have supported ancient life-though they don't yet have evidence that it did. A sample of rock driled by the Curiosity Rover  revealed conditions that could have supported ancient microbes at some point in the distant past. The news of even potential life made headlines, and there's no doubt the discovery of actual microbial life on Mars would, too. But the impact on finding life on another world might not be as Earth shattering as one might think, experts say.