How extreme and widespread is the California drought? Images recently released by NASA' Gravity Recovery and Climate Experiment, or GRACE, show an ever-worsening situation.
Launched in 2002, NASA's twin satellites are making "detailed measurements of Earth's gravity field which will lead to discoveries about gravity and Earth's natural systems." More at the JPL GRACE site, and the University of Texas site.
The images are not photographs, but rather show how much groundwater has been lost over time. At left, June 2002, a few months after GRACE launched. Center, June 2008. At right, June 2014.