Opportunity exploring areas which were once shallow lakes on Mars

NASAs Mars Opportunity rover has started exploring areas on the Red Planet, which scientists believe were once shallow lakes.

London, Sept 13 : NASA's Mars Opportunity rover has started exploring areas on the Red Planet, which scientists believe were once shallow lakes.

The area where Opportunity is now exploring, lies near Mars's equator and is called Meridiani Planum and scientists believe water once formed shallow lakes here.

These lakes dried up, and mineral deposits from the desiccated lakebeds were eroded by wind and water and deposited again as sandstone, said rover scientist Ray Arvidson of Washington University in St Louis, Missouri, US.

"What we're going to try to do as we go down [into Victoria] is to look at key rocks with all our instruments and use all this to further understand and test this hypothesis," New Scientist quoted Arvidson, as saying.

He said Opportunity has now finally started on its long awaited descent into Victoria Crater.

Opportunity first reached the 800-metre-wide crater in September 2006. Mission managers then had Opportunity circle the crater rim for several months, searching for a gentle gradient that would allow for an easy entry and exit.

However, a severe dust storm engulfed the Red Planet, reducing solar power to Opportunity and its twin, Spirit, forcing the rover team to postpone the crater entry.

The storms finally died down in August, allowing the rovers to start moving again.

On Wednesday, the rover team commanded Opportunity to drive four metres into the crater and then come back up towards the rim to test the driving conditions on the slope.

The team had ordered the rover to stop driving if it experienced more than a 40 percent slip rate. A 100 percent slip rate would mean the rover was spinning its wheels but not moving at all.

After driving three metres back up towards the rim, the slip rate passed the 40 percent threshold, so Opportunity stopped short of returning to its starting position.

The rover team is now assessing the results of the drive to plan out the descent into the crater.

The meteorite impact that created Victoria crater has exposed layers of bedrock 30 metres deep, about six times deeper than anything Opportunity has so far examined on the planet.

Astronomers believe this bedrock laid down billions of years ago will reveal how conditions evolved over longer timescales and whether Mars once had conditions suitable for life.

ANI