In a news conference at the American Geophysical Union NASA’s Curiosity mission team presented a measured, low-key and hype-free discussion about the first use of Curiosity’s full array of analytical instruments.
What they have found are chlorinated hydrocarbons – simple organic molecules made up of carbon, chlorine and hydrogen, sulphur-containing compounds, and calcium perchlorate.
Perchlorates are salts that, when dissolved in water, lower the freezing temperature of that water. The presence of those salts could enable water to stay liquid in the near-surface layers of martian soil. This could provide a possible habitat for Martian microbes.
The discovery of perchlorates supports the 2008 finding made by NASA’s Phoenix lander, which detected perchlorate salts in soil samples from Mars’s north polar region. Being a stationary craft, Phoenix could only take limited samples and used a simpler “wet-chemistry” analytical instrument.