Solar storms spewing out a jet of radiation and charged particles at millions of miles per hour usually have little effect on Earth because of the planet's protective magnetic field although strong space storms can cause problems with satellites and electronics and communication systems.
Mars, without a similar protective magnetic field, will bear the brunt of the current solar storm, experts said.
"Space weather can be nasty!" geologists Ken Herkenhoff of the rover's science team wrote from the USGS's Astrogeology Science Center explaining the decision to put the rover to sleep.
The rover has been in the middle of sorting out another problem caused when one its two redundant computers developed memory problems. Engineers had switched Curiosity to a backup computer during troubleshooting, a process that has been put on hold to wait out the solar storm, Wired.com reported Thursday.
Curiosity has been in a "safe" mode as engineers worked repair the computer problems to resume science operations.
"Storm's a-comin'! There's a solar storm heading for Mars. I'm going back to sleep to weather it out," the rover tweeted from its official feed from NASA's Jet Propulsion Laboratory in Pasadena, Calif.