According to NASA, the Curiosity rover has taken significant steps toward understanding how Mars may have lost much of its original atmosphere. Learning what happened to the Martian atmosphere will help scientists assess whether the planet ever was habitable. An important indicator is whether there is any methane present in the atmosphere. Scientists want to know about methane in the Martian atmosphere because life as we know it produces methane and most methane in Earth's atmosphere is due to biological processes. Today's first set of results came back negative for methane, meaning at present there appears to be no modern-day life. However these are preliminary results and NASA says that the hunt has just begun in earnest and not to draw any final conclusions yet.