NASA’s Opportunity rover is set to explore the edge of a crater just above Mars’ ‘Perseverance Valley,’ to uncover new clues on the processes that left rocks scattered across its floor.
A new color-enhanced image captured just before the Mars rover’s ‘walkabout’ survey kicked off shows a landscape that looks almost like a beach here on Earth, and scientists suspect water may have played a role in the rocks’ transportation.
The region may once have hosted a perched lake in the crater rim’s crest which acted as a spillway, the researchers say – or, they may have eroded in place by wind.
NASA’s Opportunity rover is set to explore the edge of a crater just above Mars’ ‘Perseverance Valley,’ to uncover new clues on the processes that left rocks scattered across its floor. A new color-enhanced image captured just before the Mars rover’s ‘walkabout’ survey kicked off shows a landscape that looks almost like a beach here on Earth
‘The walkabout is designed to look at what’s just above Perseverance Valley,’ said Opportunity Deputy Principal Investigator Ray Arvidson of Washington University in St Louis.
‘We see a pattern of striations running east-west outside the crest of the rim.’
Opportunity has been investigating the areas on and around the western rim of the 14-mile-wide Endeavour Crater, which sits just above Perseverance Valley, since 2011.
Part of the crest at the top of the valley is marked by a broad notch, the researchers say.
And, just west of the feature, there are elongated patches of rocks lining a slightly depression.
The experts say this may have been a drainage channel billions of years ago.
‘We want to determine whether these are in-place rocks or transported rocks,’ Arvidson said.
‘One possibility is that this site was the end of a catchment where a lake was perched against the outside of the crater rim.
‘A flood might have brought in the rocks, breached the rim and overflowed into the crater, carving the valley down the inner side of the rim.
MARS: A WET PLANET
Evidence of water on Mars dates back to the Mariner 9 mission, which arrived in 1971. It revealed clues of water erosion in river beds and canyons as well as weather fronts and fogs.
Viking orbiters that followed caused a revolution in our ideas about water on Mars by showing how floods broke through dams and carved deep valleys.
Mars is currently in the middle of an ice age, and before this study, scientists believed liquid water could not exist on its surface.
In June 2013, Curiosity found powerful evidence that water good enough to drink once flowed on Mars.
In September of the same year, the first scoop of soil analysed by Curiosity revealed that fine materials on the surface of the planet contain two per cent water by weight.
Last month, scientists provided the best estimates for water on Mars, claiming it once had more liquid H2) than the Arctic Ocean – and the planet kept these oceans for more than 1.5 billion years.
The findings suggest there was ample time and water for life on Mars to thrive, but over the last 3.7 billion years the red planet has lost 87 per cent of its water – leaving it barren and dry.
‘Another possibility is that the area was fractured by the impact that created Endeavour Crater, then rock dikes filled the fractures, and we’re seeing effects of wind erosion on those filled fractures.’
The researchers say examining the rocks along what could be a channel could help to reveal more about the site’s history.
The team is using stereo images of the valley to plot the rover’s route.
Opportunity recently hit a bump in the road, after the steering actuator on its left-front wheel stalled with the wheel turned outward more than 30 degrees.
The region may once have hosted a perched lake in the crater rim’s crest which acted as a spillway, the researchers say – or, they may have eroded in place by wind
But even after the June 4 setback, the wheel was straightened out to a more favourable orientation on June 17.
While the robot has six wheels, each with its own drive motor, it now only uses steering motors on its rear wheels.
It stopped using the right-front wheel’s steering motor after 2005.
‘For at least the immediate future, we don’t plan to use either front wheel for steering, said Opportunity Project Manager John Callas of NASA’s Jet Propulsion Laboratory.
‘We can steer with two wheels, just like a car except it’s the rear wheels.
‘We’re doing exactly what we should be doing, which is to wear out the rover doing productive work – to utilize every capability of the vehicle in the exploration of Mars.’