MULTISPECTRAL MICROSCOPIC IMAGER (MMI): COMBINING MICROTEXTURE AND MINERALOGY IN THE ROBOTIC EXPLORATION OF THE MOON AND MARS

In combination with mineralogy, the microspatial relationships between framework mineral grains, pore spaces and authigenic phases (e.g. cements) comprising a rock or soil, provides data essential for inferring both primary formational, as well as secondary (diagenetic) processes. Such information can significantly enhance field-based interpretations of petrogenesis, directly supporting real time, hypothesis-driven exploration. The Multispectral Microscopic Imager (MMI) provides color microscopic views of rock surfaces where each pixel is a composite VNIR spectrum of the materials imaged. The data produced provides potentially definitive mineralogical identifications, localized within a microtextural framework. Data sets acquired with the MMI provide highly desirable geologic and contextual information to: 1) support the in situ, rover-based analysis of rocks and soils, 2) guide sub-sampling of geologic materials for return to labs on Earth and 3) support astronaut investigations during EVAs, or in a lunar base laboratory. In the context of the astrobiological exploration of Mars, such observations can also provide a basis for inferring habitability at the microscale. The MMI design employs multispectral light-emitting diodes (LEDs) and an uncooled focal plane array to achieve the low-mass (<1kg), low-cost, and high reliability (no moving parts) required for an arm-mounted instrument on a planetary rover. Development of the MMI has proceeded by the addition of spectrometric capabilities to the highly successful Microscopic Imagers (MIs) currently in operation on the Mars Exploration Rovers (MERs). The MMI, with its multiple spectral bands and spectral range extending into the infrared, produces high resolution color images that easily resolve the spatial distributions of minerals. The MMI improves upon the capabilities of current and planned microimagers, such as the Robotic Arm Camera (RAC) onboard the Phoenix lander and Mars Science Laboratory's Mars Hand Lens Imager (MAHLI), by extending the spectral range into the infrared, and by increasing the number of spectral bands. To showcase the microtextural and mineralogical capabilities of the MMI, we present results obtained from a variety of lithotypes considered potential analogs for Mars and the Moon.