.Hematite is often tied to iron-rich water. This deposit may have precipitated from a standing body of water on Mars that existed for thousands to hundreds of thousands of years or longer.
And where there once was water, there could have been life.
Beacon for exploration
"There is really no doubt that this is hematite," said Philip Christensen, a senior Mars researcher at Arizona State University in Tempe. "Were not confusing this with anything else," he said.
Christensen said that the accumulation of hematite was discovered by the Thermal Emission Spectrometer (TES) instrument on the now-orbiting Mars Global Surveyor. He has tagged the find the "Meridiani Formation," the first rock formation identified by mineralogical composition on Mars.
The deposit of hematite is thought by Christensen to be compelling evidence of sedimentary origin. "This is a site where water has been present long enough to form mineralization," he said.
"This is a beacon that says water was here", Christensen said. "Liquid water was stable at or near the surface in this region early in Mars history. Its an important beacon of an interesting place to go," he said.
High on the list
The hematite is not only important as a signature of ancient water, said Carlton Allen, astromaterials curator at the NASA Johnson Space Center in Houston, Texas. "Hematite is one of a limited number of minerals known to be associated with the preservation of microscopic evidence of life," he said.
Iron oxides, including hematite, have been found here on Earth to preserve microbes through geologic time.
"Hematite on Earth is found under unusual and unique conditions, and often it is associated with water," said James Head, a planetary geologist from Brown University. "Plus, hematite deposits seem to be associated with microscopic life. Thats why everybody is excited," Head told SPACE.com.
Head said dropping a rover into the hematite-laden Sinus Meridiani site is "high on the list" for scientific desirability. "We are trying to pick areas that can test some significant scientific hypotheses. Thats important for the future. We are not only going to learn how to do this -- operate on Mars and select samples to bring back -- but were going to be addressing significant problems at the same time," he said.
Allen of NASA said the twin rovers are well equipped to address questions of exobiology at Sinus Meridiani and are capable of recognizing macroscopic evidence for microscopic life.
"A key function of the 2003 Mars Exploration Rovers may be to discover and certify prime sites for the next decades Mars sample return missions," Allen said.
RAT Patrol
Each of the Mars Exploration Rovers that will land on the Red Planet in early 2004 totes the Athena science payload. The rovers will literally be "armed" with instruments and tools for geologic exploration of the Martian surface.
Along with souped-up camera hardware, spectrometers and other devices, each of the highly mobile rovers is outfitted with a robotic arm.
The arm is replete with a turret of devices, including a microscopic imager and a Rock Abrasion Tool, or RAT for short.
"What weve tried to do is come up with a robotic field geologist," said Steve Squyres, a planetary scientist at Cornell University in Ithaca, New York. Squyres is also leading the team that is developing the Athena science payload.
The robot arm can place the RAT against a rock. Using two mechanical grinding wheels, material can be removed from a rock. The exposed region can then be inspected by the suite of instruments on the Athena science payload.
The Athena package appears ideal to truck into areas and study hematite deposits up-close-and-personal. If so, where the second rover will be sent to explore is sure to be hotly debated.
"Having two rovers gives you the ability to double-up on science by going to two scientifically different places," Squyres said.
advertisement
