IT’S like threading a needle while travelling faster than the speed of sound. Pilots at the US air force test pilot school flew this supersonic T-38C jet to the right place at the right time so that NASA could capture this photograph of the jet’s shock waves. When the waves are forced together, they merge into one, creating a sonic boom.
This is the first time shock waves have been photographed from the ground in such detail. The technique takes advantage of the sun both as a very bright light source and as a background. Edward Haering at NASA’s Armstrong Flight Research Center in California and his team used a special optical filter to reveal the sun’s textured surface, stippled with sunspots. This meant the team could make hundreds of detailed observations of each shock wave by observing how it distorted the pattern of sunspots.
7 October 2015