NASA's Spirit, the first of two Mars Exploration Rovers on the martian surface, has stood up and extended its front wheels while continuing to delight its human partners with new information about its neighborhood within Mars' Gusev Crater.
Traces of carbonate minerals showed up in the rover's first survey of the site with its infrared sensing instrument, called the miniature thermal emission spectrometer or Mini-TES.
Although carbonates form in the presence of water, more time is needed to ascertain whether the amounts detected come from interaction with water vapor in Mars' atmosphere or are evidence of a watery local environment in the past, scientists emphasized.
"We came looking for carbonates. We have them. We're going to chase them," said Dr. Phil Christensen of Arizona State University, Tempe, leader of the Mini-TES team.
Previous infrared readings from Mars orbit have revealed a low concentration of carbonates distributed globally. Christensen has interpreted that as the result of dust interaction with atmospheric water. First indications are that the carbonate concentration near Spirit may be higher than the Mars global average.
After the rover drives off its lander platform, infrared measurements it takes as it explores the area may allow scientists to judge whether the water indicated by the nearby carbonates was in the air or in a suspected ancient lake.
"The beauty is we know how to find out," said Dr. Steve Squyres of Cornell University, Ithaca, N.Y., principal investigator for the mission. "Is the carbonate concentrated in fluffy dust? That might favor the atmospheric hypothesis. Is it concentrated in coarser material? That might favor the water hypothesis."