NASA's Mars rover Opportunity reached the rim of "Victoria Crater" in Mars' Meridiani Planum region. The rim of the crater is composed of alternating promontories, rocky points towering approximately 70 meters (230 feet) above the crater floor, and recessed alcoves. The bottom of the crater is covered by sand that has been shaped into ripples by the Martian wind.
Scientists studying initial on-the-scene images relayed from NASA's Opportunity Mars rover at Victoria Crater are elated.
The enormous impact crater has been the six-wheeled robot's long-term destination for the past 21 Earth months.
"For the first day or two after we saw the initial images we were just overwhelmed," said Steve Squyres, lead Mars Exploration Rover scientist from Cornell University in Ithaca, New York.
The far side of the crater is about one-half mile (800 meters) away from where the Mars machine is positioned.
"Now that the reality of the scene has sunk in and the features have started to become familiar, we're beginning to think carefully about the science and about our plan of attack," Squyres told SPACE.com.
Clockwise or counterclockwise
Rover handlers back here on Earth are in the process of acquiring sweeping Panoramic Camera (Pancam) shots of the crater. After that, the plan is to drive Opportunity to a spot called "Cape Verde" - a large promontory and a spot for taking more Pancam imagery.
Squyres said that a partial circumnavigation of the crater is on tap. "We haven't decided yet whether we'll head clockwise or counterclockwise," he added.
A future decision is whether or not to steer Opportunity into Victoria Crater.
"We want very much to drive into the crater, because that's where the geology is! Whether or not we'll do it, though, depends on an assessment of how steep the slopes are," Squyres noted.
To help determine whether Opportunity will make tracks and take on that daring maneuver, long-baseline stereo images are needed. These are produced as Pancam images taken from two different locations on the crater's rim. Doing so would generate a good model of the terrain, Squyres advised.
"We're not going to make any decisions about driving in or not driving in until we understand the slopes a lot better than we do now," Squyres emphasized.
Die at any moment
Could Victoria be a final resting spot for Opportunity?
Scientists on the rover team clearly view Victoria Crater as impressive real estate. And given the wide open spaces surrounding Victoria at Meridiani Planum of less scientific interest, perhaps the robot should spend its final days at the site.
"Victoria could be the final resting spot for Opportunity," Squyres said, just like Low Ridge could be the final resting spot for the Spirit Mars rover, also busy at work at Gusev Crater, another exploration zone on the red planet.
"These rovers are so far past their design lifetime that they could die at any moment," Squyres pointed out.
"Every sol [a day on Mars] could be our last. We're going to use every capability that Opportunity has to understand this crater and the story it has to tell as well as we can. That's going to take a long time. If the rover's still alive once we're done, then we'll see what we see," Squyres concluded.
The sightseeing on Mars from Opportunity's vantage place is staggering, explained William Farrand, a research scientist at the Space Science Institute in Boulder, Colorado and a member of the Mars Exploration Rover science team.
"I think the thing that most impresses me is the sheer size of Victoria Crater and the associated outcrops compared with things we've seen thus far in the mission," Farrand told SPACE.com.
In the images transmitted from the rover, sometimes blocks and boulders at first appear really big, Farrand said. But when scientists actually figure out the actual scale, those objects turn out to be not that large - only a meter or a couple of meters in size.
"Victoria crater is actually pretty darn big," Farrand said, adding that the feature that's an eye-popping 2,428 feet (740 meters) in diameter. "It's about three quarters of the size of Meteor Crater in Arizona...and if you've been there...you know it is pretty big," he said.
Whole new mission
Farrand said that first looks at Opportunity images of Victoria show that outcrops exposed in the rim are large in size. Victoria crater, in map view, consists of a number of promontories and incut regions which Mars researchers are, at least for now, referring to as "capes" and "bays".
Currently, Opportunity is at "Duck Bay", Farrand explained, named after a site visited by Portuguese maritime explorer, Ferdinand Magellan and his crew. To the north of the rover is a promontory now named "Cape Verde" - another spot visited by Magellan and a huge block, roughly 33 feet (10 meters) or so high.
"With regards to what the rocks will tell us or whether it is what we expected, it is just too early to say. We have a lot of work ahead of us to understand the crater and its outcrops," Farrand stressed. 'It is like a whole new mission."