Description

A roughened gallium nitride (GaN) surface, reminiscent of the lunar terrain on which Neil Armstrong and Buzz Aldrin touched down exactly fifty years ago. The craters come from a lack of crystal growth around foreign particles, which were present in their respective centers.

This image was captured with scanning electron microscopy, which detects a highly accelerated and tightly focused beam of electrons interacting with a solid sample and converts the collected signal into a grayscale image.