Viking Reconsidered

The first attempt to find life on Mars was carried out by the Viking landers in the 1970s.  Viking conducted three tests, positive results from any of which would have strongly suggested life, according to scientists before the misson.  In fact, positive results were obtained, but the science community, perhaps reasonably, backed away from making the big call, arguing strange soil chemistry on Mars could have produced the results.

Since then, scientists have learned much more about Martian soil.  The Phoenix Lander a few years ago dug into Mars and found perchlorates in the soil.  Curiosity has recently found the same.  It turns out that perchlorates, a form of salt, could have skewed the Viking results, but it also strengthens the case for possible life when linked to water, as they are on Mars.

So, did Viking find life nearly forty years ago?  We might know later this century.