Image of MAHLI instrument


The Mars Hand Lens Imager, called MAHLI, is the rover's version of the magnifying hand lens that geologists usually carry with them into the field. MAHLI's close-up images reveal the minerals and textures in rock surfaces.

Tech Specs

Main Job Microscopic Imaging of minerals, textures and structures in rocks and soil at scales smaller than the diameter of a human hair.
Location Mounted on the turret at the end of the robotic arm.
Color Quality Similar to that of consumer digital cameras, with an autofocus ability.
Image Size Up to 1600 x 1200 pixels
Image Resolution Possibility of 13.9 microns/pixel
Focal Length In focus from 18.3 mm at the closest working distance to 21.3 mm at infinity
Focal Ratio and Field of View From f/9.8 and 34° to f/8.5 and 39.4°
Memory 8 Gigabyte flash memory storage; 128 megabyte synchronous dynamic random access memory (SDRAM)
HD Video 720p
Other First sends back thumbnails so scientists can select best images to send back to Earth

Mars Hand Lens Imager (MAHLI)

Mastcam image of the Mars Hand Lens Imager (MAHLI) on Curiosity's arm, during the 30th Martian day, or sol, of the rover's mission on Mars (Sept. 5, 2012).
Mastcam image of the Mars Hand Lens Imager (MAHLI) on Curiosity's arm.

Second only to the rock hammer, the hand lens is an essential tool of human geologists. Usually carried on a string around the person's neck, the hand lens helps a geologist in the field identify the minerals in a rock. The robotic geologist, Mars Science Laboratory, carries its own equivalent of the geologist's hand lens, the Mars Hand Lens Imager (MAHLI).

MAHLI provides earthbound scientists with close-up views of the minerals, textures, and structures in martian rocks and the surface layer of rocky debris and dust. The self-focusing, roughly 4-centimeter-wide (1.5-inch-wide) camera takes color images of features as small as 12.5 micrometers, smaller than the diameter of a human hair. MAHLI carries both white light sources, similar to the light from a flashlight, and ultraviolet light sources, similar to the light from a tanning lamp, making the imager functional both day and night. The ultraviolet light can be used to induce fluorescence to help detect carbonate and evaporite minerals, both of which indicate that water helped shape the landscape on Mars.

MAHLI's main objective is to help the Mars Science Laboratory science team understand the geologic history of the landing site on Mars. MAHLI also helps researchers select samples for further investigation.