If a coronal mass ejection with the intensity of the Carrington event1 or more hit Mars, what would happen to an astronaut on its surface who is too far from their base to return to in time? Assuming they have travelled too far in a Mars roving vehicle, and the solar flare hits now, would they survive, or for a limited time? Would the flare knock out the Mars roving vehicle's power unit? Mars has a thin atmosphere and weak magnetic fields.
As for the base, I'm assuming it is underground so that a solar flare wouldn't have much impact there.
1The Carrington Event was a powerful geomagnetic storm on September 1–2, 1859, during solar cycle 10 (1855–1867). A solar coronal mass ejection (CME) hit Earth's magnetosphere and induced the largest geomagnetic storm on record. The associated "white light flare" in the solar photosphere was observed and recorded by British astronomers Richard Carrington and Richard Hodgson. The storm caused strong auroral displays and wrought havoc with telegraph systems. The now-standard unique IAU identifier for this flare is