NASA has not yet found any scientifically supported evidence of extraterrestrial life.

We have scanned the heavens and sent robotic scouts to our planetary neighbors. Yet, the search has turned up empty. NASA's astrobiologists confirm that we have not discovered life on any other planet. No signals, no microbes, no footprints. We are still, as far as science can prove, completely alone. But our search has only just begun. We have barely scratched the surface of Mars, leaving vast oceans of cosmic mysteries entirely untouched.