The remote sensing technologies on the Global Surveyor spacecraft have yielded enough new information about the geology of Mars that planetary scientists will still be studying it for decades to come, and yet the planetary geologists could hardly be more excited about what promises to be an incoming flood of new and different data from the instruments on Odyssey. Arizona State University Korrick Professor of Geology Philip Christensen, the principal investigator for Mars Global Surveyor's Thermal Emission Spectrometer (TES) and also for 2001 Mars Odyssey's Thermal Emission Imaging System (THEMIS) is still getting data from TES. However, thanks to a significant expansion of his team's facilities, he and his colleagues are prepared and eager to begin receiving and analyzing an additional stream of data from an even more powerful instrumental array.
On February 22, Christensen and fellow scientists will dedicate a newly remodeled and greatly expanded set of high tech facilities in the Moeur Building, an historic adobe structure on the ASU campus. NASA officials will be present, as will a group of students from Nogales, Arizona, who will be among the first of thousands of middle and high school students who will participate in Mars imaging and remote sensing alongside the scientists in a NASA/ASU education program called the Mars Student Imaging Project. Measuring the infrared signatures of minerals on the martian surface, TES produced the first global mineral map of Mars and provided the mineralogical roadmap for geologists and geochemists following the trail to water's past on Mars.
Says Christensen, "From TES we learned what minerals were present, where former hydrothermal systems might have been located, the mineral compositions of the dust, ice and rocks on Mars, and we've got a lot of interesting ideas of where might be the most interesting and unique places on the Martian surface."
With THEMIS, Christensen now hopes to start focusing on these unique locations because what sets THEMIS apart from its predecessor is high spatial resolution. Compared to TES, the images THEMIS sends back to earth are thirty times clearer.
According to Christensen, "It's like if you sent a survey out to map the west and you discover the Rocky Mountains, the Sierra Nevadas and the great deserts - you do an inventory of what's out there, and then you start focusing on places like Yellowstone, places that are unique and different from every place else."
For this greater focus, THEMIS is equipped to study the Martian surface on two fronts. THEMIS is a two-camera thermal emission imaging system. In addition to collecting information about Martian surface minerals from the infrared heat they emit, THEMIS also collects data from reflected sunlight. THEMIS collects infrared information using 10 spectral bands, and visible light using 5 bands.
Using its improved infrared capabilities, THEMIS will continue TES's mission to determine the mineralogy of the Martian surface, map the entire planet, and identify where ancient, wet environments - and possibly life - may have once existed on Mars. On this front, THEMIS will also search for temperature anomalies associated with active subsurface hydrothermal systems (such as heat coming from active volcanic areas).
Using its visible light capabilities, THEMIS will help fill in informational gaps between large-scale geological images from the Viking orbiters in the 1970s and the very high-resolution images from MGS. Essentially, THEMIS will provide a more comprehensive map of the particular features of Mars' geology and geography.
This information is key to NASA's upcoming 2003 Mars Exploration Rovers mission, which plans to send two rovers equipped with remote sensing equipment to the surface of Mars. Christensen and his team at ASU are preparing smaller versions of his instrument to be installed on the rovers. In order to know where the rovers should land, researchers like Christensen want to know not only where the most interesting mineral deposits are located, but also in which of these sites the rovers will best be able to maneuver.
The science team's first THEMIS images are tentatively scheduled to be released at a NASA press conference at the Jet Propulsion Laboratory on March 1.
The first student imaging project, to be performed by a high school class from Schaumberg, Illinois, will begin on March 17 and will be featured on a broadcast of "Live from Mars" on March 19. The first scientific findings by this student group will be released at a public press conference at ASU at 11 a.m. on March 20. At that time, a second student group, students from Nogales, Arizona will be at the facility acquiring their image and will be available for interview.
The ASU Mars Student Imaging Project is an outreach activity of Arizona State University, developed initially in connection with research activities involving the Thermal Emission Spectrometer experiment on the Mars Global Surveyor. The Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science. See http://mars.jpl.nasa.gov/odyssey/.
THEMIS was developed at Arizona State University, Tempe, with Raytheon Santa Barbara Remote Sensing, Santa Barbara, Calif. Lockheed Martin Astronautics, Denver, is the prime contractor for the project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena. For more information on THEMIS, see http://themis.asu.edu/index.html .