PASADENA, Calif. — As the second part of NASA’s twin assault on Mars got under way, the rover Opportunity gave scientists breathtaking photographs of terrain very different from anything they had seen before.
Meridiani Planum "is the smoothest, flattest place we’ve ever investigated on Mars," said Matt Golombek, a science team member for the Mars Exploration Rovers mission at the Jet Propulsion Laboratory in Pasadena, Calif.
Like its twin rover Spirit, which landed on the other side of the planet, Opportunity revealed enticing clues about the martian surface by stirring up the surface material as it bounced across the crater floor cushioned by large, energy-absorbing airbags.
In its wake were clearly visible sets of circular and radial impressions in the soil, said Jim Bell, lead scientist for the Panoramic Camera from Cornell University. Those impressions were the earliest data on the makeup of the martian soil within the crater and a sign of what to expect when the rover begins moving across the crater floor, Bell said.
"These marks are telling us something about the physical properties of the material. We are leaving an indent in this soil," Bell said. The airbags appear very clean, with that material not sticking like that seen at the Spirit Mars rover site in Gusev Crater.
In its landing, Opportunity made a figure eight within the small crater as it tumbled end-over-end, down-and-up, up-and-down the crater walls before coming to a full stop. Golombek said the robot’s Panoramic Camera (Pan Cam) already has provided some tantalizing glimpses over the crater’s rim to the outstretched landscape that Opportunity will eventually explore.
An initial attraction for the scientists is a group of rocks just a modest drive away from where the rover temporarily sits. Early images showed layers in those rocks, some no thicker than a finger. These layered rocks measure only 10-centimeters tall and scientists were already debating whether they were volcanic ash deposits or sediments carried by water or wind.
Bell said more detailed shots of that outcrop are planned from where the rover now sits. Finding a spot in the exposed rock that exhibits multiple types of materials would be ideal. That would allow Opportunity to conduct a type of "one-stop-shopping" for science in one driving session.
"It would be irresponsible not to study that material which could provide some key to the action of water in this area," Bell said.
Golombek said he is hopeful that Opportunity’s Mini-Thermal Emission Spectrometer will identify compositional variations in the rock outcrop. There is also a "strong desire" to trench in the soil with the rover’s wheels while still within the crater. "It’s all sitting there for us," he said.
By press time Friday, NASA’s second Mars rover had successfully deployed its wheels.
It was expected to wheel itself onto the flat and dark terrain of its landing spot by Feb. 1. Opportunity landed at 9:05 p.m. PST on Jan. 24.
The spot where it landed was later renamed Challenger Memorial Station in honor of the crew of the space shuttle Challenger, who perished in a launch accident Jan. 28, 1986.
