When NASA's Viking landers analyzed the surface of Mars in the mid-1970s, they detected tiny amounts of organic compounds —basic microbial forms of life, fundamental to any evidence of more complex organisms. At the time, however, these findings were reportedly dismissed as contaminants from Earth that came from the landers themselves.
This week at a meeting of high-profile speakers on the topic of extraterrestrial life, astrobiologist Dirk Schulze-Makuch asserted that the compounds weren't necessarily stray Earth remnants. When the lander samples were discovered, he explained, water was added to them with the assumption that in a moistened environment, the microbes would become more energized and easier to examine. Instead, the hydration may have done the opposite, essentially drowning the samples.
In Schukze-Makuch's view, there's only one way to test the hypothesis that these compounds are native to Mars. "We need a new mission to Mars dedicated primarily to life detection," he argued. "I cannot wait for such a mission to get under way."