NASA's Mars Opportunity rover jeopardised in dust storm the size of North America

Opportunity rover shifted to 'minimal operations' to preserve power through intensifying sand storm

NASA has suspended operations for its Mars Opportunity rover as the result of a dust storm that has prevented the vehicle from recharging its batteries for more than a week.

The storms - covering an area equivalent to the size of North America - started on Friday 1 June, but still haven't abated, with NASA receiving its last transmission from the vehicle on Sunday morning.

A dark, perpetual night has settled over the rover's location in Mars' Perseverance Valley

"Sunday's transmission was especially good news considering the dust storm has intensified in the past several days," explained NASA's latest update.

It continued: "A dark, perpetual night has settled over the rover's location in Mars' Perseverance Valley. The storm's atmospheric opacity - the veil of dust blowing around, which can blot out sunlight - is now much worse than a 2007 storm that Opportunity weathered.

"The previous storm had an opacity level, or tau, somewhere above 5.5; this new storm had an estimated tau of 10.8 as of Sunday morning."

The rover is enduring the storm in temperatures of minus 29 degrees celsius, although one benefit of the dust storm, which could damage the vehicle, is that it reduces the extreme fluctuations in temperature on the red planet's surface.

However, if it runs out of power, the rover's heaters will switch off and the device might not be able to restart.

NASA's Opportunity rover was originally designed for a 92-day mission starting in January 2004. It has investigated soil and rock samples and taken panoramic photos while roving from its original landing site at Eagle Crater, through Marathon Valley to its current storm-strewn location, not far from the massive Endeavour Crater.

Before the storm struck, the team responsible for communicating with, and controlling, Mars Opportunity were able to make contingency plans.

The rover was shifted to "minimal operations" on Wednesday 6 June in order to preserve battery power. Should its power run down entirely, the rover's ‘survival heaters' will stop working, leaving it vulnerable to the cold.

A much larger dust storm in 2007 is believed to have accounted for Opportunity's sister rover, Spirit.

Last week, NASA released details from Mars' surface gleaned from its Curiosity rover, which has been exploring Mars' surface since August 2012. Analysis of rocks taken from the bottom of Gale Crater by Curiosity rover found more evidence of organic material, indicating that Mars might once have been hospitable enough to have hosted life.