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Starfish Prime was a high-altitude nuclear test conducted by the United States, a joint effort of the Atomic Energy Commission (AEC) and the Defense Atomic Support Agency. It was launched from Johnston Atoll on July 9, 1962, and was the largest nuclear test conducted in outer space , and one of five conducted by the US in space.
Quando a bomba nuclear Starfish Prime explodiu, partículas carregadas da detonação colidiram com moléculas da atmosfera da Terra, criando uma aurora artificial que pôde ser vista até na Nova Zelândia.
Starfish Prime foi um teste nuclear de alta altitude conduzido pelos Estados Unidos, um esforço conjunto da Comissão de Energia Atômica (AEC) e da Agência de Apoio Atômico de Defesa. Foi lançado do Atol Johnston em 9 de julho de 1962 e foi o maior teste nuclear realizado no espaço sideral e um dos cinco realizados pelos EUA no ...
- Overview
- Cold War heats up
- Nuclear lift off
- Fallout
The results from the 1962 Starfish Prime test serve as a warning of what might happen if Earth’s magnetic field gets blasted again with high doses of radiation.
It was pitch black when Greg Spriggs’ father brought his family to the highest point on Midway Atoll on July 8, 1962. That night on another atoll a thousand miles away, the U.S. military was scheduled to launch a rocket into space to test a fusion bomb.
“He was trying to figure out which direction to look,” Spriggs recalls. “He thought there was going to be this little flicker, so he wanted to make sure everybody was going to see it.”
Spectators were also holding “watch-the-bomb parties” in Hawaii, as the countdown was broadcast over shortwave radio. Photographers aimed their lenses toward the horizon and debated the best camera settings for capturing a thermonuclear explosion in outer space.
It turned out that the blast—a 1.4 megaton bomb, 500 times as powerful as the one that fell on Hiroshima—was not subtle.
“When that nuclear weapon went off, the whole sky lit up in every direction. It looked like noon,” says Spriggs. Starfish Prime exploded at an altitude of 250 miles, at about the height where the International Space Station orbits today. For as long as 15 minutes after the initial explosion, charged particles from the blast collided with molecules in Earth’s atmosphere, creating an artificial aurora that could be seen as far away as New Zealand.
A year before, in 1961, international negotiations to ban nuclear testing had taken a turn for the worse. After three years of no testing, the Soviet Union and the U.S. had broken from a voluntary moratorium, with the Soviets conducting 31 experimental blasts, including Tsar Bomba, the largest nuclear bomb ever detonated. It was set off in October 1961, about 13,000 feet above an island in the Arctic Circle.
The space race was in its infancy back then, and the U.S. military didn’t have many qualms about sending almost anything into space. The Department of Defense was in the midst of a separate project to put 500 million copper needles into orbit to try to reflect radio waves and help long-distance communication. There was even a plan, which ultimately fizzled, to set off a nuclear blast on the moon.
Scientists and military figures were keen to know what would happen if a nuclear explosion were set off in space, especially how it might interact with Earth’s magnetosphere. Just two years earlier, America’s first satellite, Explorer 1, accidentally discovered that Earth is encircled by donuts of intense radiation held in place by its magnetic field. They were subsequently named Van Allen belts after James Van Allen, the University of Iowa scientist who discovered them.
The Sounds of the Van Allen Belts
NASA’s Van Allen Probes recorded these chorus waves in space above Earth. These waves are created by electrons spiraling along magnetic field lines around Earth. They then interact with other electrons in the region to accelerate them to higher speeds or push them into Earth’s upper atmosphere.
“As Van Allen said when he discovered the radiation belts, space is not empty, space is radioactive,” says David Sibeck, a scientist for NASA’s Van Allen Space Probes mission. “Van Allen’s discovery was worrying because it said any future spacecraft or astronaut that we send up is going to be exposed to this radiation. And that was a shocker back then.”
After four days of delays, waiting for the perfect weather, Starfish Prime was launched on the tip of a Thor rocket from Johnston Atoll, an island about 750 nautical miles southwest of Hawaii. The military also sent up 27 smaller missiles laden with scientific instruments to measure its effects. Airplanes and boats got into position to record the test in as many ways as possible. Flares were set off in hopes of distracting local birds from the blinding flash to come.
Scientists already knew that a nuclear blast in space behaves very differently from one on the ground, says Spriggs. There is no mushroom cloud or double flash. People on the ground don’t feel a shock wave or hear any sound. There’s just a bright ball of plasma, which appears to change color as charged particles from the blast are pushed down into the atmosphere by Earth’s magnetic field. This effect generates colorful artificial auroras, and is why these high-altitude nukes were sometimes called “rainbow bombs.”
It came as a surprise how bad it was, and how long it lasted, and how damaging it was to satellites that flew through that area and died.
ByDavid SibeckNASA
As Earth’s magnetic field caught ionized radiation from the Starfish Prime test, it created a new artificial radiation belt that was stronger and longer lasting than scientists had predicted. This unexpected “Starfish belt,” which lingered for at least 10 years, destroyed Telstar 1, the first satellite to broadcast a live television signal, and Ariel-1, Britain’s first satellite.
“It came as a surprise how bad it was, and how long it lasted, and how damaging it was to satellites that flew through that area and died,” Sibeck says.
Still, the test revealed some important information about radiation around Earth. The bomb released a special isotope tracer called cadmium-190. Its original purpose was to track the fallout from the test, but it also became a valuable resource for understanding weather patterns in the upper atmosphere.
The test also helped the U.S. understand how to detect nuclear detonations in space and build a system, later called Vela Hotel, to monitor tests by other countries. Such advances helped make a treaty to ban nukes in space more realistic.
But there are other potent sources of radiation in outer space. There is a very small chance, Sibeck says, that a solar flare at just the right moment could hit the planet with a similar amount of radiation.
“It would have to be bigger than most of the ones that we’ve ever seen during our lifetimes or during the space age,” he says. “But there are [geomagnetic] storms that have been that big, and we know that’s happened because people have seen aurorae at mid-latitudes or even lower at the dawn of technological civilization.”
The largest geomagnetic storm ever recorded, called the Carrington Event, hit Earth in 1859. It caused auroras over Australia and gave electrical shocks to telegraph operators in America. If a similar storm hit today, the consequences would be much more serious than downed telegraph lines.
“A lot more things depend on computer chips and power than they did in 1962. Things in your house, things in your car, communications. It would be much worse,” Sibeck says.
9 de jul. de 2012 · 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.
The Starfish Prime electromagnetic pulse also made those effects known to the public by causing electrical damage in Hawaii, about 1,445 kilometres (900 mi) away from the detonation point, knocking out about 300 streetlights, setting off numerous burglar alarms and damaging a telephone company microwave link [10] (the detonation time ...
Starfish Prime foi um teste nuclear de alta altitude realizado pelos Estados Unidos em 9 de julho de 1962. Fazia parte da Operação Fishbowl. Foi o maior teste nuclear realizado no espaço sideral, com um rendimento de 1,4 megatons.
