On the Tibetan Plateau in eastern China, 4 million solar panels silently soak up the sun as part of the Longyangxia Dam Solar Park. It’s the largest solar farm in the world, spreading over 10 square miles of the high desert landscape.

The complex sprung into existence in 2013 and has been rapidly expanding ever since. Satellite imagery curated by NASA’s Earth Observatory chronicles its growth from a cluster of panels to a sprawling solar farm that looks like a giant, angular thought bubble as of January 2017.