astroengine writes "NASA's newest rover on Mars has recently used its Dust Removal Tool for the first time, clearing away a patch of rust-colored dust coating its latest target: a slab of rock called "Ekwir_1." The Dust Removal Tool, or DRT (yes, the rover's cleaning instrument is called "dirt") is a motorized brush with stainless steel wire bristles located on Curiosity's multipurpose Robotic Arm turret — a veritable Swiss Army knife of planetary exploration tools." Reader Sez Zero links to a story on the brushing action at the BBC, which adds that "Curiosity is building towards using its hammer-drill, the last major tool yet to be deployed on the mission." So at least we know there's dirt on Mars, even if they chose not to send a dedicated life sensor, too. The Aeon piece is well worth reading, if that decision sounds perverse.