The bed of Martian rock where the Curiosity rover is slated to begin drilling for the first time shows evidence of a past watery environment that has excited scientists all over again.
"This is the first time in this mission that we have not just an aqueous environment but also one that results in precipitation of minerals, which is very interesting to us," Mars Science Laboratory project scientist John Grotzinger said.
That means the area was saturated with water to such an extent that mineral deposits formed, and those areas can serve as "geochemical recorders" of the past environment.
Drilling is expected to begin within the next two weeks, at a flat area of terrain named after late MSL deputy project manager John Klein, who died in 2011.
Grotzinger called the drilling location a "sweet spot" where scientists can answer questions about how much water was in the area, whether it was flowing and how long it was there at different periods of time. They could also get a sense of whether the area was habitable.
"We can't wait to get drilling on this stuff," he said.