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Not doing this experiment again soon: 60 years ago the US created the first man-made aurora and EMP

h/t Tallbloke

Starfish Prime was the largest Nuclear test conducted in space. The 1.4 megaton explosion at 250 miles above Johnson Atoll was a US mission that launched on July 9th 1962. The Electromagnetic pulse (EMP) it generated was much bigger than expected, and knocked out a few satellites, which presumably wasn’t part of the plan. (Future tests were smaller.) The explosion and the aurora it generated was visible nearly 900 miles away in Hawaii where some street lights were blown, some phone lines went down and surges were recorded on planes. Apart from war, it’s hard to imagine this experiment could be done ever again.

The aurora itself lasted less than 15 minutes, but created a belt of MeV electrons. And as many as five years later some of those electrons were still being detected in the atmosphere.

Starfish Prime: The First Accidental Geomagnetic Storm

Dr Tony Phillips, Spaceweatherachive.com

On July 9, 1962, the US military detonated a thermonuclear warhead 250 miles above the Pacific Ocean–a test called “Starfish Prime.” What happened next surprised everyone. Witnesses from Hawaii to New Zealand reported auroras overhead, magnificent midnight “rainbow stripes” that tropical sky watchers had never seen before. Radios fell silent, then suddenly became noisy as streetlights went dark in Honolulu.

From a Spaceweather post last year:

A new paper just published in the research journal Earth and Space Science .. (by)  Love et al describe how a high-altitude nuclear blast jerks Earth’s magnetic field. First, the EMP ionizes a layer of air underneath the bomb. This layer presses downward, pinning Earth’s magnetic field lines in their pre-blast locations. Next, as the ionization subsides, the magnetic field springs back. It’s a sort of heaving, lurching geomagnetic storm.

Handy for finding submarines too apparently?

At twilight after the burst, resonant scattering of light from lithium and other debris was observed at Johnston and French Frigate Shoals for many days confirming the long time presence of debris in the atmosphere. An interesting side effect was that the Royal New Zealand Air Force was aided in anti-submarine maneuvers by the light from the bomb. — Wikipedia

 


National Geographic

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.

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