Just before halting its investigations, the nuclear-powered rover used the drill at the end of its 7-foot-long robotic arm to bore into a rock near where it landed and analyze the powder.
Scientists need to be sure that when the big hammer tool turns in a rock it breaks the surface into a useable powder that will not clog or damage the sample handling mechanism.
The subsequent analysis will reveal the precise chemical and mineralogical compositions present in the powder, giving scientists clues as to the likely conditions under which the rock formed.