Researchers have released a detailed geological map of Northeast Syrtis Major, one of the prime candidate landing sites for NASA’s next Mars rover, scheduled for launch in 2020.
Within Northeast Syrtis are the mineral signatures of four distinct types of watery and potentially habitable past environments. Those minerals had been detected by prior research, but the new map shows in detail how they are distributed within the region’s larger geological context. That helps constrain the mechanisms that may have formed them, and shows when they formed relative to each other.
The lowest and the oldest layer exposed at Northeast Syrtis has the kind of clay minerals formed when rocks interact with water that has a fairly neutral pH. Next in the sequence are rocks containing kaolinite, a mineral formed by water percolating through soil. The next layer up contains spots where the mineral olivine has been altered to carbonate—an aqueous reaction that, on Earth, is known to provide chemical energy for bacterial colonies. The upper layers contain sulfate minerals, another sign of a watery, potentially life-sustaining environment.
Understanding the relative timing of these environments is critical, Mustard says. They occurred around the transition between the Noachian and Hesperian epochs—a time of profound environmental change on Mars.
This press release is very much an effort by these scientists to influence the final landing site choice. They like this site, and they want to convince other scientists that are part of the project to agree with them.