Click For Photo: http://i.dailymail.co.uk/1/2018/06/13/15/wire-3284268-1528901792-669_636x382.jpgClick For Video: http://video.dailymail.co.uk/video/bc/rtmp_uds/1418450360/2015/07/07/1418450360_4342829155001_4342782682001.mp4
A NASA rover on Mars has fallen silent as a gigantic dust storm envelops the planet and blots out the sun.
Flight controllers tried late Tuesday night to contact Opportunity, but the rover did not respond.
Storm - End - May - One-quarter - Planet
The storm has been growing since the end of May and now covers one-quarter of the planet.
Controllers expect it will be several more days before there's enough sunlight to recharge Opportunity's battery through its solar panels.
NASA - Battery - Clock - Spacecraft - Checks
NASA says the battery is likely so low that only a clock is still working, to wake the spacecraft for periodic power-level checks.
NASA launched the twin rovers Opportunity and Spirit in 2003 to study Martian rocks and soil.
Spirit - Years - Opportunity - Mission - Lifetime
Spirit hasn't worked for several years. Opportunity, however, has kept exploring well past its expected mission lifetime.
'The team is now operating under the assumption that the charge in Opportunity's batteries has dipped below 24 volts and the rover has entered low power fault mode, a condition where all subsystems, except a mission clock, are turned off,' NASA said.
Rover - Mission - Clock - Computer - Power
The rover's mission clock is programmed to wake the computer so it can check power levels.
If the rover's computer determines that its batteries don't have enough charge, it will again put itself back to sleep.
Due - Amount - Dust - Perseverance - Valley
Due to an extreme amount of dust over Perseverance Valley, mission engineers believe it is unlikely the rover has enough sunlight to charge back up for at least the next several days.
The Martian dust storm that has blotted out the sun above Opportunity has continued to intensify.
Storm - May - Square - Miles - Square
The storm, which was first detected on May 30, now blankets 14-million square miles (35-million square kilometers) of Martian surface - a quarter of the planet.
When the orbiter team saw the storm nearing Opportunity, they notified the rover's team to begin preparing contingency plans.
Matter - Days - Storm
In a matter of days, the storm had ballooned. It...
Wake Up To Breaking News!