AIR & SPACE MAGAZINE Penny in the Martian Dust Curiosity calibrates its camera NASA/JPL-Caltech/MSSS/Planetary Science Institute October 8, 2013 The Mars Curiosity rover needs a way to keep its instruments calibrated, so for the Mars Hand Lens Imager (MAHLI), it keeps a U.S. penny aboard. The camera took this ultra-high resolution image on October 2, showing all the Martian dust it's collected in just over a year on the planet. Image: NASA/JPL-Caltech/MSSS/Planetary Science Institute NASA/JPL-Caltech/MSSS/Planetary Science Institute Get the latest stories in your inbox every weekday.