The rover has not responded to attempts at contact from NASA engineers, which means its batteries have probably dipped to the point at which it is in low power fault mode.
The rover's batteries are likely to be so low that only a clock is still working, to wake the spacecraft for periodic power-level checks, according to officials.
NASA says the Martian dust storm has "blotted" out the view of the sun from the rover, which uses solar panels to provide power and to recharge its batteries.
"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", a Tuesday night NASA update explained.
Dust events help shape the surface of Mars, making it critical for NASA to understand the ancient and modern climates on the Red Planet. As stated by John Callas of the NASA JPL in Pasadena, California, "we are anxious, but we hope the storm will break and the rover will communicate with us again". "This would be like forecasting El Niño events on Earth, or the severity of upcoming hurricane seasons".
It's not like a desert storm shifting large sand dunes, more like talcum powder lofted into atmosphere and distributed around the globe, said Jim Watzin, director of the Mars Exploration Program at NASA Headquarters. "Regardless of what happens, this little rover has been a great investment to help us explore the Red Planet".
The storm is already worse than a 2007 storm that Opportunity survived. Occasionally, they can balloon into regional storms in a matter of days, and sometimes even expand until they envelop the planet. The Martian atmosphere is so thin that while the wind can lift dust off the surface, it doesn't topple a spacecraft.
The Mars Reconnaissance Orbiter has a special role, acting as an early warning system for weather events such as the recent storm. The orbiter's wide-angle camera-the Mars Color Imager-gave the Opportunity team advanced warning before the storm hit.
"This is the ideal storm for Mars science."
Even on the opposite side of the planet, where the Curiosity rover is parked at Gale Crater, the thick red haze nearly completely obscures the horizon. However, it usually does not reach those levels until later in the year.
Maxwell, who left NASA in 2013 for Google, notes in the spirit of anthropomorphizing common to those involved with rovers, "She did more than anyone expected from her or ever could have expected from her, and if we can all say that at the end of our lives, then we'll be as lucky as she is".