We are finally closing in on the cosmic origins of the “OMG particle”

The helicopter was flying excessive by way of the evening sky with its door barely ajar. Johannes Eser and Matthew Rodencal have been in the again controlling a laser declaring by way of the hole. They aimed in the direction of a balloon 35 kilometres above them and fired.

It appears like a scene from a spy film, however Eser and Rodencal, then at the Colorado School of Mines, have been truly testing a plan to identify ultra-high-energy cosmic rays, the most energetic particles ever found. They stream throughout the universe earlier than slamming into our ambiance and emitting a tiny flash of mild. The laser was alleged to mimic that flash.

This twilight helicopter trip occurred almost a decade in the past, however is an element of a saga that goes again to a minimum of 1991. In October that 12 months, we detected the single most energetic particle ever seen. It had the kinetic power of a bowling ball dropped from shoulder peak, crammed right into a subatomic-sized bundle. It rapidly turned referred to as the “Oh-My-God particle” and, naturally sufficient, scientists have been determined to know the place it got here from.

Since then, we’ve noticed many related particles. Huge ground-based detectors have supplied us with maps of the place they may come from, along with a shortlist of the excessive cosmic objects that might produce them. But fact be informed, we nonetheless don’t have all the solutions. That is why scientists now wish to take the cosmic ray hunt into the ambiance – and finally into house – in an effort to unravel the thriller as soon as and for all.

This story actually started with one other balloon in 1911. At that point, physicist Victor Hess climbed right into a …