The search for life elsewhere in the universe is one of the most compelling aspects of modern science. Given its scientific importance, significant resources are devoted to this young science of astrobiology, ranging from rovers on Mars to telescopic observations of planets orbiting other stars.
The holy grail of all this activity would be the actual discovery of alien life, and such a discovery would likely have profound scientific and philosophical implications. But extraterrestrial life has not yet been discovered, and for all we know may not even exist. Fortunately, even if alien life is never discovered, all is not lost: simply searching for it will yield valuable benefits for society.