Malin Space Science Systems
San Diego, California
|When:||Friday, Sept. 23, 2011, 10:30 a.m. to 11:30 a.m.
Join us for coffee beginning at 10:00 a.m.
|Where:||Seminar Conference Room, 10100 Burnet Road, Bldg 196-ROC, Austin, Texas 78758|
|Host:||Jack Holt, UTIG|
The majority of known impact sites on Earth are craters that were filled and buried in sediment; examples occur under the Chesapeake Bay and beneath the Chicago O'Hare Airport. The upper crust of Mars, with its relative lack of tectonism, is almost entirely a layered and cratered volume of filled, buried, and complexly interbedded craters, sediment, and volcanic products. The filling and burial in sediment occurred when Mars was still very young; some craters were also exhumed or partly exhumed during these early times. NASA's Mars Science Laboratory (MSL) rover, Curiosity, is planned for launch in November. Its mission is focused on assessing whether Mars once had habitable environments. In August 2012, Curiosity will land in Gale, a 155 km-diameter impact crater in which there is a section of sedimentary rock approximately 5 km thick. Gale is one of the craters that was filled, perhaps buried, and then exhumed; and this might have occurred more than once. The sedimentary rock that remains in Gale forms a mound exhibiting considerable vertical and lateral stratigraphic diversity and complexity, including multiple erosional unconformities. The mound was eroded at various times by fluvial, eolian, and mass-movement processes. The proportions of clastic sediment, tephra, and chemical precipitates are unknown; interpretations of infrared spectra acquired by orbiting instruments indicate that some of these rocks contain sulfates, clays, and mafic silicates in a distinct stratigraphic sequence. Curiosity’s field site is located in the northwestern quarter of Gale. The rover team plans to focus on the record of ancient environments in the lowermost strata, containing sulfate- and clay-bearing rocks, during MSL’s 23-month primary mission. The Mars Hand Lens Imager (MAHLI), one of 10 MSL science investigations, is a 2 megapixel color camera with a macro lens. It is mounted at the end of a 2 meter-long robotic arm. The camera can focus on targets at working distances of 21 mm to infinity; at closest range, the pictures have a resolution of 14 microns per pixel and grains of very fine sand are resolved. Because of its focus capability, the camera can provide context for its higher resolution views, it will also image the martian landscape and document drill sites and samples collected by the rover. White light and UV (365 nm) LEDs permit imaging at night, robotic arm movement is used to create mosaics and stereopairs. The instrument has 8 GB of data storage and can do onboard color interpolation and focus merging (z-stacking) of up to 8 images. The MAHLI investigation centers on testing hypotheses regarding the depositional and diagenetic environments recorded in Gale’s sedimentary strata through its capabilities to document rock color, texture, and structure.