Posted on August 9, 2004 at 4:15 p.m.

BIRMINGHAM, AL — The first 90 Martian sols (days) of the Spirit rover’s exploration in Gusev crater on Mars are featured in the August 6 issue of Science, a publication of the American Association for the Advancement of Science. Evidence gathered during the exploration suggests past presence of water on the planet.

UAB astrophysicist and Associate Professor Emeritus Thomas Wdowiak, Ph.D., is a listed author on two of the papers in the collection, which is featured as a special section. They are: "The Spirit Rover's Athena Science Investigation at Gusev Crater, Mars," which is an overview, and "Mineralogy at Gusev Crater from the Mössbauer Spectrometer on the Spirit Rover," which describes the early results obtained with that instrument on the rover's robotic arm.

Wdowiak, who became a co-investigator on the Athena Science Team in the spring of 1997, participates in the still on-going surface operations of both the Spirit and Opportunity rovers that landed respectively in Gusev crater and at Meridiani Planum in January. As a participant in the operation of the German supplied Mössbauer spectrometers, he is a payload uplink lead and a payload downlink lead in the Science Operations Working Group responsible for exploration.

Mössbauer spectroscopy uses nuclear gamma radiation to examine iron-containing minerals and is particularly suited for the robotic rover exploration of Mars. Wdowiak was an early advocate for this usage. The Mössbauer spectrometer on board Spirit has identified the minerals olivine, pyroxene, magnetite and hematite. The measurements reveal a generally igneous and basaltic nature (as in volcanic areas) for the rocks and soil within Gusev, with an indication of some modification that suggests there may have been episodes of aqueous activity (presence of water) in certain places during ancient time around 3-4 billion years ago.

Gusev crater, just south of the Martian equator, is 160 kilometers across (approximately 100 miles) and is breached at the southern rim by a valley that could have once brought water into parts of the crater. The size of the crater and the position of the Spirit landing site near the center, allows only a glimpse from the rover of the distant crater wall. Spirit has moved a few kilometers from the landing site and is now ascending the Columbia Hills, which were named in honor of the Columbia Space Shuttle astronauts.

Wdowiak has 25 years of experience using Mössbauer spectroscopy in the investigation of meteorites, thermal springs on land and thermal vents in the deep sea, as well as global mass extinction events caused by asteroids or comets striking the Earth.

Wdowiak plans to continue his "robotic astronaut" activity exploring Mars with the Spirit and Opportunity rovers as long as those vehicles continue to function.