Picture of a Jet Breaking the Sound Barrier

According to the Museum of Hoaxes, this is a real photo.

Does anyone know what the shape is around the plane -- why it happens and what accounts for its shape? Or is it a hoax after all?

someone with more technical knowledge will correct me in 4, 3, 2 ..

They must have some real good camera equipment to take a STILL photo at that speed with that much clarity... let alone the timing, or did they waste a ton of film shooting just and before the plane went into Mach?

I hear it's doing very well in flight tests. It's prefered 2 to 1 over the F-31 Acetylsalicylic

All of them actually.

Whooooooooooohoooooooooo

a fighter circled my neighborhood three or four times - enough so that it caused me to go outside to look. Shortly after I went outside, the pilot fired up his afterburners. He didn't break the sound barrier, but he sure made a LOT of noise over this residential area. I'm guessing he was saying "hello" or "goodbye" to someone in the area.

Cool picture!

Edit: punctuation

fuel tanks with burritos.

They are splitting atoms in there.

The Hoax Museum Answer page links to a Navy website.

From the Navy Site:
How the Shot Was Made:

At sea aboard USS Constellation, July 7, 1999 — An F/A-18 Hornet assigned to Strike Fighter Squadron One Five One (VFA-151) breaks the sound barrier in the skies over the Pacific Ocean, July 7, 1999. VFA-151 is currently deployed with USS Constellation (CV 64). U.S. Navy photo by Ensign John Gay. Ens. Gay, photo officer for Fighter Squadron Two (VF 2), shot this image from the 0-10 level weather deck (the uppermost deck on the island) of USS Constellation (CV 64). It was shot with a Nikon N-90s with a Nikon 70-300 ED zoom lens, using Kodacolor 200 negative film. The camera was set for manual exposure of F/5.6 at 1/1000 sec. The image was acquired with a single shot, panned from left to right, prefocused at approximately 200-300 yards off the port side of the ship, where the aircraft flew by. This image has appeared in many publications worldwide. <990707-N-6483G-001> July 7, 1999.

High-Resolution Photo Available Here.

You do not need to be above Mach 1 to make a shock cone like that, or so I have been told.

When a body travels at speeds near to the speed of sound and beyond it creates a shock wave, a zone where air is highly compressed. You can think of that zone as the area where the sound of the planes passing is trying to keep up with the plane itself, but failing.

The foggy effect comes from that compression. It is water vapor being "squeezed" out of the air by the shock waves compression. When the shock wave has passed the air "uncompresses" and the fog converts back to vapor.

Two things to note:

First, this effect doesn't happen only in the instant the speed of sound is broken. It happens for as long as the planes speed remains in the transonic/supersonic range, and remains where humidity is high enough for vapor to be squeezed out into fog. Video of this effect would show a plane flying past, surrounded by a consistent "lifesaver" of fog. It also doesn't happen when humidity is low, such is often the case at higher altitudes where planes usually fly supersonically.

Second: Note the little patch of fog just behind the planes cockpit? That's because a shockwave forms behind any shape that protrudes into the airstream in a major way.

Still a cool effect, nonetheless.

I am majorly impressed. That's exactly what I was looking for.

Now, do you know what speeds this effect happens at? It sounds like it really has nothing to do with the speed of sound.

This actually does have something to do with the speed of sound. When an object moves through air, it creates pressure waves in that air. Those waves move forward and "warn" the air ahead to move out of the way before the object gets there. Those pressure waves move at the speed of sound.

When a plane moves at or above the speed of sound the pressure waves can't move forward fast enough. The air ahead get's no warning, and that causes a shockwave.

It happens before the plane reaches the speed of sound because As the plane moves forward the air has to move as well, to make room for the plane. That adds up to transonic airflow.

For a plane in level flight, it's got to be real close to sonic. The speed of sound near sea level is (I think) about 700 mph. I honestly don't know specifics, but I'd guess a plane would need to be above 680 mph?

(BTW, thanks, but no need to be impressed. Everyone has areas they pay special attention too. One of mine happens to be airplanes.)

That first video's what I'm talking about. That plane is probably moving through zones of differing humidity. Where it's humid enough the shock wave makes the fog appear, and when the shock wave has passed by the fog is gone too.

Good finds!