Mars rover to explore huge crater

Nasa is sending its Opportunity rover looping around a gaping crater rimmed with rocky cliffs that may have formed long ago in a salty ocean.

Opportunity will spend the next several weeks carefully circumnavigating Endurance crater and photographing its gaping interior from multiple angles.

Eventually, scientists may send the rover skidding into the crater, if they determine it is safe to do.

The crater is 430 feet across and up to 66 feet deep, its bottom carpeted in a patchwork of dunes.

“There are cliffs the rover could roll off and die if we’re not careful,” rover driver Brian Cooper said of the route around the rim.

“It’s the most spectacular view we’ve seen of the Martian surface, for the scientific value of it but also for the sheer beauty of it,” said Cornell University astronomer Steve Squyres, the mission’s main scientist.

The bulk of the bedrock is deeper below the surface, and therefore older, than a far smaller outcrop half a mile away.

Scientists know the older rocks now exposed at Endurance crater are different but cannot say yet what conditions were like when they originally formed.

Sending Opportunity even part of the way into the crater would enable the robotic geologist to study the rocks up close, determine their origin and learn if water played a role in its history.

But the slope and dry soil inside the crater combined could make it slippery enough to prevent the six-wheeled Opportunity from rolling back out again.

Scientists on the €670m mission said the potential scientific payoff could justify consigning the rover to a crater it couldn’t escape. Opportunity and its twin, Spirit, are expected to last at least through September.