Half a century after the first successful Mars landing, Viking's greatest legacy may be the questions it taught us to ask.

Add Yahoo as a preferred source to see more of our stories on Google. The cathedral in Odense houses the remains of Viking king Knud IV. Johan Tobias Joensen/Visit Odense/dpa-tmn Once upon a time, ...

Fifty years ago, NASA’s Viking missions to Mars made groundbreaking attempts to detect life on the Red Planet. While the missions initially returned negative results, a new study published in the ...

The redemption of Viking: Did the 50-year-old mission to Mars find life or not? How NASA’s 1975 mission to Mars led to decades of scientific controversy and confusion over the existence of life on ...