Look at the shock wave in your diagram. It's at a 45 degree angle at Mach 1, which is what it should be - sound waves traveling 1 for 1 from its source at Mach 1 (i.e., 45 degree angle).
Again in your diagram, "The faster the speed, the sharper the shock wave." - agree.
But in the image posted by the OP, the waves are at least 80 degrees perpendicular to the aircraft! So what's up with the NASA image of two aircraft flying faster than the speed of sound?
The images feature two T-38s from the US Air Force, flying at supersonic speeds less than nine metres (30 feet) apart, with a stream of shockwaves emanating from either side.
I would like to see a zoomed out version of the NASA image. Perhaps then one could better see the curvature of the wave front.
Even so, there is "sumpin" odd about the speed at which the wave must propagate (i.e., faster than the speed of sound) to have such a perpendicular departure from something that is itself traveling at sonic velocities.
Look at the shock wave in your diagram. It's at a 45 degree angle at Mach 1, which is what it should be - sound waves traveling 1 for 1 from its source at Mach 1 (i.e., 45 degree angle).But in the image posted by the OP, the waves are at least 80 degrees perpendicular to the aircraft! So what's up with the NASA image of two aircraft flying faster than the speed of sound?
First, it's just a diagram. the shock wave is exaggerated for effect. Shock waves develop perpendicular to the airstream. Since Thrust SSC was just at the speed of sound when that photo was taken, the shock wave is nearly 90 degrees. Since the jets are traveling at supersonic speeds, the shock wave is angled rearward.
Below is a shot done the same way that shows the bow wave.
Here's a web site that provides a simple explanation of the pressure wave generated by the airplane traveling through the air. (See: High-Speed Aerodynamics – Shock Waves)
