In 1976 the twin Viking Lander spacecraft touched down on the surface of Mars and began the first ever, search for extraterrestrial life. Onboard where three miniaturized biology laboratories each with a unique focus on how to look for microbial life on Mars. Of the three biology instruments on each Viking Lander, the Labeled Release experiment designed by Dr. Gilbert V. Levin, obtained intriguing results that Levin says is consistent with microbial metabolism.