Written by Vedika Pathania, a second-year student.

Yes. Before you read the headline again, yes, the United States really did explode a nuclear bomb in space and the test was called Starfish Prime. Starfish Prime was a high-altitude nuclear test performed on July 9, 1962 as part of Operation Fishbowl, a series of tests.

Starfish Prime was not the first on the list when it came to high-altitude tests, but it was certainly the biggest nuclear test ever carried out by the US in space. The test resulted in the discovery and understanding of the nuclear electromagnetic pulse (EMP) effect, as well as a mapping of tropical and polar air mass seasonal mixing rates.

Why and when?

This took place at the height of the Cold War and its nuclear weapons race. In October 1961, the Soviet Union had carried out the world’s biggest nuclear explosion, the 50 megaton Tsar Bomb. Political tensions reached an all-time high in nuclear testing in 1962, with 178 tests, more than double the yearly Cold War norm. During the Cuban Missile Crisis, only three months after the release of ‘Starfish Prime,’ the world was on the verge of nuclear disaster.

Its immediate impacts were felt for thousands of kilometres, but it also had a long-term impact that continues to affect us now. The Cold War was a terrifying era. Concerned that a Soviet nuclear bomb detonated in orbit may damage or destroy US intercontinental missiles, the US set up Project Fishbowl (which was part of the broader Operation Dominic) to take it on their own shoulders to find out for themselves what happens when nuclear weapons are detonated in space. There had been previous high-altitude testing, but they had been rushed and the findings were ambiguous. Fishbowl was designed with a more scientific approach in mind.

One of the blast’s early effects was a massive aurora visible for thousands of kilometres. Electrons are light and fly away from the explosion quickly. Because a magnetic field affects a travelling electron, these electrons travelled swiftly down the Earth’s magnetic field lines and were released into the upper atmosphere. They were halted by the atoms and molecules of Earth’s atmosphere at a height of around 50-100 kilometres. The energy of the electrons was absorbed by those atoms and molecules, and they responded by shining, generating an artificial aurora.

The effects, however, were considerably more than just a light display. When the bomb went off, those electrons were accelerated to tremendous speeds. They produce a short but highly strong magnetic field when this happens. An electromagnetic pulse, or EMP, is what this is termed. The pulse was so powerful that it impacted the flow of electricity hundreds of kilometres distant on Earth! Hundreds of lamps were blown out in Hawaii, and there were widespread phone disruptions. Electrical surges on flights and radio blackouts were among the other impacts.

Scientists foresaw the EMP, but the Starfish Prime pulse was far greater than projected. There was also another consequence that had not been adequately foreseen. Many of the electrons from the blast remained in space for months, trapped by Earth’s magnetic field, forming an artificial radiation belt high above our planet’s surface. When a high-speed electron collides with a satellite, it can cause a mini-EMP. The specifics are complicated, but the end result is that these electrons may zap satellites and cause electrical damage. At least six satellites were damaged by the Starfish Prime detonation’s surge of electrons.

Scientists and engineers were taken aback by the entire effect. They had anticipated something considerably smaller, and certainly not on the scale that transpired. We gained a better knowledge of the physics of EMPs after learning about them from Starfish Prime, as well as information into how to mitigate their impacts. A nearby supernova or gamma-ray burst (a type of super-supernova) would have very comparable effects, and might potentially influence our atmosphere directly. The good news is that no supernovae or GRB progenitors are close enough to cause us harm. However, because our Sun circles the galaxy, there may have been a moment, millions or billions of years ago, when one did go off close.

Key points summary

• Starfish Prime was a high-altitude nuclear test performed on July 9, 1962, at the height of the Cold War.
• The test resulted in the discovery and understanding of the nuclear electromagnetic pulse (EMP) effect
• One of the blast’s early effects was a massive aurora visible for thousands of kilometres.
• At least six satellites were damaged by the Starfish Prime detonation’s surge of electrons.
• We gained a better knowledge of the physics of EMPs after learning about them from Starfish Prime, as well as information into how to mitigate their impacts.

Want to write for us? Submit your story here. You can also apply to become a news anchor. Apply here