The Rover Environmental Monitoring Station (REMS) on NASA’s Curiosity Mars rover includes temperature and humidity sensors mounted on the rover’s mast. One of the REMS booms extends to the left from the mast in this view.
Spain provided REMS to NASA’s Mars Science Laboratory Project. The monitoring station has provided information about air pressure, relative humidity, air temperature, ground temperature, wind and ultraviolet radiation in all Martian seasons and at all times of day or night.
This view is a detail from a January 2015 Curiosity self-portrait. The self-portrait, at http://photojournal.jpl.nasa.gov/catalog/PIA19142, was assembled from images taken by Curiosity’s Mars Hand Lens Imager.