Curiosity is trying to determine whether a piece of sandstone would be an appropriate place to drill for a specimen to analyze. This piece of sandstone, to be precise.

What is it and NASA looking for?

John Grotzinger, Curiosity Project Scientist from the California Institute of Technology, said in a statement, “We want to learn more about the wet process that turned sand deposits into sandstone here. What was the composition of the fluids that bound the grains together? That aqueous chemistry is part of the habitability story we’re investigating.” For the researchers, analyzing the “cement,” material that fills the space between the grains of sand in the rock, can determine if the rock developed in wet conditions.

And if it did, were Percival Lowell’s canals there once after all? Well, probably not. Nonetheless, finding out that the rock was formerly partially or totally submerged will offer up more questions to be asked.