Can you see the shock?

Why a cone forms above Mach 1

Anything moving through air pushes on it, and the push travels outward at the speed of sound. Below Mach 1 those pressure disturbances run ahead of the aircraft and the air has time to move aside; above Mach 1 the aircraft outruns them, so the pressure changes become strong, abrupt jumps: shock waves.¹ Drawn as circles emitted by a moving point, the geometry does the rest. When the point is faster than the circles grow, the circles share a common tangent, a cone, whose half-angle μ obeys sin μ = 1/M.²

Many shocks, then two

A real aircraft is not a point. NASA’s explainer puts it plainly: an aircraft creates shock waves around all its components, “nose, cockpit, wings, engine inlets, tail and any bump the air must move around”.¹ As those waves travel toward the ground they tend to pile up on each other, “eventually leaving only two that reach the ground as a sonic boom”.¹ From 55,000 ft that journey takes almost a minute, by which time the aircraft is miles ahead of its own boom.¹

That is the whole ambition of the X-59: a shape intended to keep its shocks from coalescing, so that what reaches the ground is a softer “thump” rather than a boom.¹ Whether it does is what the aircraft’s upcoming acoustic validation phase is for, and as of 7 September 2026 that phase was still ahead.³ The research brief keeps that distinction.

Seeing it for real

Photographs of shock waves exist. NASA notes that schlieren imaging “makes normally invisible changes in air density visible”, and its sonic-boom explainer illustrates the point with an image from NASA’s 2019 air-to-air schlieren flights, which shows a T-38 rather than the X-59.¹ This page does not reproduce that image: the reuse terms of the specific file were not recorded when this page was written, so the original drawing above stands in for it. If you look the image up, it is worth remembering which aircraft it shows.

Read the research brief →Back to the subsonic console →

Sources

1. NASA, Quesst blog, “NASA X-59 Explainer: Science of Sonic Booms”, 10 August 2026 (Nicolas Cholula). Body: pressure changes above Mach 1 as strong rapid jumps; shocks around all components; waves pile up leaving two at the ground; almost a minute from 55,000 ft; the X-59’s intended “thump”; schlieren sentence and the T-38 image caption. nasa.gov
2. NASA Glenn Research Center, Beginner’s Guide to Aeronautics, “Mach Angle” (editor Nancy Hall, last updated 13 May 2021). Body: “sin(mu) = 1 / M”, “mu = asin(1 / M)”; in supersonic flow small disturbances are transmitted downstream within a cone. Read 7 September 2026. grc.nasa.gov
3. NASA, Quesst blog, “NASA’s X-59 Aircraft Builds Momentum Through 25th Flight”, 4 September 2026. Body: the “upcoming acoustic validation phase”. nasa.gov

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