NASA Mars Exploration Rover Status Report, January 25, 2019: Mars atmospheric opacity (tau) over the rover site is uncertain due to recent storm activity.
No signal from Opportunity has been heard since Sol 5111 (June 10, 2018) during the historic global dust storm. Opportunity likely experienced a low-power fault, a mission clock fault and an up-loss timer fault. The team is continuing to listen for the rover over a broad range of times, frequencies and polarizations using the Deep Space Network (DSN) Radio Science Receiver.
The team is continuing to command “sweep and beeps” throughout each daily DSN pass to address a possible complexity with certain conditions within mission clock fault on the rover. Since loss of signal, over 600 recovery commands have been radiated to the rover. [More at link]