All over the world, but particularly in the UK and America, people are hearing mysterious booming noises. They often occur at the same time every day, and the same booms are heard across distances of hundreds of kilometres.

What are these mysterious booms? Are they being made by a new secret aircraft? And how are they related to strange doughnut-shaped contrails that have been seen high up in the sky?


You probably know that when aircraft go supersonic, breaking through the sound barrier, they make a booming noise. A sonic boom is caused by an object travelling faster than the speed of sound. An aircraft flying through the air creates a pressure wave in front of it, and one behind it.

These waves travel at the speed of sound. When the aircraft speeds up, the waves become compressed together. And as a plane reaches the speed of sound, it is now travelling as the same speed as the waves, and the waves become one single and huge wave that creates that booming noise.

In fact, unlike the popular myth, the boom does not just happen when the aircraft reaches the speed of sound – it continues all the time that the plane flies faster than sound.

(Incidentally, the “crack” of a whip is also a sonic boom, where the whip tip moves faster than sound.)


Aircraft can create sonic booms. However, normally aircraft do not fly faster than the speed of sound anywhere near places where people live, because of restrictions about aircraft disturbing people. Supersonic flights are, in effect, banned over land and over coastal areas. The booms created by military aircraft flying supersonically will only be heard far out at sea.

And the booms made by a military aircraft is only heard for a few kilometres behind the aircraft.

The new and mysterious sonic booms are completely different – they are much louder, come from much higher in the sky – and they are heard simultaneously across distances of hundreds of kilometres.

The loudness of a boom depends on the energy creating it, which is related to the size and speed of an aircraft. These new booms are not being made by a military fighter – they have been heard by former pilots who confirm the booms are much louder. The booms are heard across a wide area. The project creating the boom could be a huge plane, but a normal plane that large would be visible. And observers have never seen an aircraft in the sky when one of these booms happens.

So, if the booms are not so loud because the aircraft is very large, then they must be created by an aircraft that flies much, much faster than normal military supersonic jets. The fastest military jets fly at Mach 2 – that is, twice the speed of sound, or about 2,500 km/h – and the fastest ever was the SR-71, which flew at Mach 3 but is no longer in active service.

Experts believe these new booms are being made by something flying much, much faster – at what are called hypersonic speeds, of 5 or even 10 times the speed of sound.

According to all the world’s military, they don’t have aircraft that can fly that fast!


There is an answer that experts are now suggesting.

They believe these booms are made by a top secret, hypersonic aircraft that flies so fast, it could fly around the world in an hour. And to fly this fast, it must fly many times higher than the highest airliner – on the edge of space.

There seems to be no doubt that this new type of aircraft is a secret military plane; like the U-2 or SR-71 from the 1950s and 1960s. It could be a spy plane, flying so high no other aircraft or missile could catch it. Or it could even be a spaceplane, a military vehicle that takes off and lands like a normal aircraft, but that can reach space itself.

Whatever this plane is, it is almost certainly American. We know the USA spends trillions of dollars on secret military programmes- and the last new hi-tech planes they revealed were the Stealth fighter and bomber in the 1980s. They have never revealed a successor to the SR-71, which they stopped using in the 1980s.

But experts believe the US does have a hypersonic plane that is creating these booms as it flies at colossal speeds. They even point to a programme called Aurora, which appeared as a line in a military budget in 1985, by mistake. The budget mentioned Aurora as $455m allocated for “black aircraft production”. When journalists asked about Aurora, the US government denied it existed, even though it was in the budget!

And by the 1990s, there were the first reports of these new loud sonic booms over the US and Britain, the US’s closest military ally. There were one or two reports, including by military pilots, of a huge triangular shaped plane. The most famous example of this was a sighting over the North Sea (the European sea between the UK and Scandinavia), when oil rig workers saw a large triangular-shaped plane being escorted by two conventional military fighters.

There were also sightings of very strange contrails associated with the booms – instead of the usual white line of vapour aircraft create, these contrails looked like a series of ring doughnuts on a piece of string. These contrails show that this aircraft does not use a conventional jet engine, or a rocket engine like space rockets or space shuttles. This type of contrail must come from a new type of engine, that pulses rather than fires constantly.

And in California, booms were heard that were so strong, they actually appeared on earthquake detectors. Seismologists who were used to seeing the results of space shuttle flights and normal military aircraft, said that these booms were not created by anything they had ever seen before. Their knowledge meant they could determine the height and speed of the aircraft, and the said it was flying at 27km up in the air, travelling at Mach 5 (2 and a half times faster than the fastest military jets).

Aviation experts and journalists agree that there is a secret US military aircraft causing these booms. And we are sure that it is no coincidence that the booms are heard most often in California (near the Area 51 base), and on the west coast of Scotland on the UK, where there is a remote air base with an enormously-long runway – exactly the type of runway needed for such high-speed aircraft.