MARDI Peeks Under Curiosity

This pair of images shows the Martian surface captured by NASA's Curiosity rover using its Mars Descent Imager (MARDI) camera on Nov. 7, 2024, the 4,357th Martian day, or sol, of the mission. The raw image on the left has not been processed; on the right is the same image after being processed on Earth to reveal additional details in the camera's images, which were taken after sunset, when the lighting is more uniform than the harsh shadows that occur earlier in the day. MARDI was designed to capture images from below the rover as Curiosity descended to the surface on Aug. 5, 2012. (Those images were later assembled together to create the first video of a descent to the Martian surface.) After landing, the mission repurposed MARDI as a surface camera. They use it to take a snapshot at the end of every drive to document the changing terrain and textures the mission has come across during its exploration of Gale Crater and the 3-mile-tall (5-kilometer-tall) mountain within it, Mount Sharp. MARDI views the surface just behind the rover's left front wheel, which is visible in the images. While it is not in sharp focus on the surface (the camera was designed to capture the long-range imaging during descent) but is able to resolve features as small as a few millimeters (0.1 inch). Likewise, because MARDI wasn't intended to be a surface camera, it lacks a dust cover. As a result, its dusty lens mutes colors and details. The first version of the pair of images above was processed onboard the rover into a color image. Once scientists back on Earth receive such images, they perform additional processing to improve contrast and sharpness, and to correct for distortions caused by the camera's fisheye lens (the curved edges of the final image are the result of correcting for those distortions). Because of that additional processing, MARDI has provided a useful way to study rock layering, textures, mineral veins, wheel tracks, and sand ripples – all of which are apparent in the second, processed, image here. Occasionally scientists will take a series of images while Curiosity drives, creating an image strip that documents changes across the surface. When the rover remains stationary (such as when it's collecting and processing a rock sample) a series of images can reveal the movement of windblown sand. https://photojournal.jpl.nasa.gov/catalog/PIA26516