What was previously thought to be a contaminate is now being viewed by NASA scientists as a new way to search for evidence of life on Mars. Scientists are reexamining results from the 1970s Viking missions against data collected in 2008 from the Phoenix Mars Lander, and are questioning whether to re-think their methods of searching for life on other planets.
The situation arose through the discovery of two chemicals—chloromethane and dichloromethane—classified as organics, which were previously thought to be contaminates when they were found in Martian soil. The Phoenix Lander is causing scientists to reexamine the discovery of these two chemicals through the consideration of another chemical—perchlorate—that has been found to destroy the evidence of the two organics. By heating the perchlorate, it becomes a strong oxidant and destroys the other chemicals, which means NASA could have had evidence of life over 30 years ago but missed it.
Further study will be conducted in 2012 with the launch of the Curiosity Rover. Curiosity will rove all over the planet and conduct soil sample tests, checking for organics and using different methods of analysis. Its alternative methods of analysis will help determine whether data from previous missions was destroyed through the testing methods that were conducted.
“This doesn’t say anything about the question of whether or not life has existed on Mars, but it could make a big difference in how we look for evidence to answer that question,” said NASA researcher Chris McKay.