The awesome power and energy released is difficult to wrap your head around. Think on this: a cubic meter of water weighs a ton. Now imagine taking a single cubic meter of water and lifting it, say, 100 meters in the air, accelerating it to several hundred kilometers per hour.
Now look again at that plume. How many cubic meters of water were are in it? Even being conservative I’d say it was in the millions, meaning millions of tons of water blasted upward and outward by the force of the explosion. It’s terrifying. And mind you, the test shown was for a relatively small blast: about an 8 or 9 kiloton yield (the equivalent of 8-9 thousand tons of TNT), whereas big nukes are capable of 20 megatons, over a thousand times the explosive yield shown.
I’m fascinated by big bangs – from the first one, to supernovae, and all the way down to bombs we humans make in our clever and plodding attempts to kill one another. Every now and again it’s good to get a solid reminder of just what these explosions are capable of.
On July 9, 1962 — 50 years ago today — the United States detonated a nuclear weapon high above the Pacific Ocean. Designated Starfish Prime, it was part of a dangerous series of high-altitude nuclear bomb tests at the height of the Cold War. Its immediate effects were felt for thousands of kilometers, but it would also have a far-reaching aftermath that still touches us today.
In 1958, the Soviet Union called for a ban on atmospheric tests of nuclear weapons, and went so far as to unilaterally stop such testing. Under external political pressure, the US acquiesced. However, in late 1961 political pressures internal to the USSR forced Khrushchev to break the moratorium, and the Soviets began testing once again. So, again under pressure, the US responded with tests of their own.
It was a scary time to live in.
The US, worried that a Soviet nuclear bomb detonated in space could damage or destroy US intercontinental missiles, set up a series of high-altitude weapons tests called Project Fishbowl (itself part of the larger Operation Dominic) to find out for themselves what happens when nuclear weapons are detonated in space. High-altitude tests had been done before, but they were hastily set up and the results inconclusive. Fishbowl was created to take a more rigorous scientific approach.
Boom! Goes the dynamite
On July 9, 1962, the US launched a Thor missile from Johnston island, an atoll about 1500 kilometers (900 miles) southwest of Hawaii. The missile arced up to a height of over 1100 km (660 miles), then came back down. At the preprogrammed height of 400 km (240 miles), just seconds after 09:00 UTC, the 1.4 megaton nuclear warhead detonated.
And all hell broke loose.
1.4 megatons is the equivalent of 1.4 million tons of TNT exploding. However, nuclear weapons are fundamentally different from simple chemical explosives. TNT releases its energy in the form of heat and light. Nukes also generate heat and light, plus vast amounts of X-rays and gamma rays – high-energy forms of light – as well as subatomic particles like electrons and heavy ions.
When Starfish prime exploded, the effects were devastating. Here’s a video showing actual footage from the test, 50 years ago today:
As you can see, the explosion was roughly spherical; the shock wave expanding in all directions roughly equally since there is essentially no atmosphere at that height. Another video has many more views of the test; I’ve linked it directly to those sequences, but if you start at the beginning it’s actually an hour-long documentary on the test.
Nuke ’em ’til they glow
This is a video that starts slow, but around 3 minutes in… well. It shows every nuclear bomb explosion on the Earth from 1945 — the US test before the bombs dropped on Japan — to 1998, when India and Pakistan joined the madness.