Researchers have detected one of the most powerful cosmic rays ever seen slamming into Earth — but they have no idea what caused it or where it came from. The extremely energetic particle, which has been named after a Japanese goddess, arrived from the direction of a void in the universe where almost nothing is known to exist, according to new research.
Cosmic rays are highly energetic particles, mainly consisting of protons or helium nuclei, that are constantly raining through every square inch of the universe (including our bodies). But a small subsection of cosmic rays, which hit Earth roughly once per square mile every year, are accelerated to even greater energy levels by some of the universe’s most intense phenomena.
These extra-energetic particles, known as “ultra-high-energy cosmic rays,” have at least one exa-electron volt (EeV), or 1 quintillion (1 followed by 18 zeros) electron volts, of energy, which is around a million times more energetic than the fastest particles from human-made particle accelerators.
On May 21, 2021, researchers detected one of these supercharged cosmic rays with the Telescope Array project — a detector made of individual substations covering more than 270 square miles (700 square kilometers) in Utah. This particular particle had a whopping 244 EeV of energy, which makes it the most energetic cosmic ray since the “Oh My God” (OMG) particle in 1991 — the most powerful cosmic ray ever detected, which had an energy of 320 EeV and traveled at more than 99.9% the speed of light.
It wasn’t a beam, it was a single particle slamming into the atmosphere. When it comes to particles like this, it’s yes/no on whether they arrive. They don’t lose energy as they travel.
As for the source, it would have been energetic to say the least. Less sterilising planets and more eating large stars like smarties.
Amusingly the actual energy was around 4 joules. An obscene energy for a particle, but tiny on human standards. (About 1 second of phone battery usage)
Yea, “beam” was a misnomer from my side. I basically meant “whatever part from that source hit us”. It could just be an absolute singular event, accellerated by a cosmic cataclysm or doing a swing-by maneuver around an event horizon. I simply assumed an omnidirectional source.
They don’t? As my physics teacher once said: “Gravity does not sleep.” Any particle with mass interacts with the rest of the Universe (within limits, OK), so it can be assumed that it actually lost energy on the way. Which, in a way, makes it even more scary.
The “far away” thing was about particles spreading to the law of square, and how many of those particles near the source where they would be much more common could do to whatever had been there. Imagine something like Earth getting hit by, e.g. a bucket full of this “stuff”.
4J is a lot for a single particle, where one usually thinks in multiples of 1.6x10⁻¹⁹J…
Agreed on all points.
The gravity drag would be tiny however. The gravitational gradient in deep space is tiny, it’s being dragged forward almost as much as backwards. Further, (with a 2 mass approximation) it’s reliant on both masses. The equivalent mass of a photon is via E = MC^2 . Therefore M=E/C^2 . Plug the numbers and this Uber photon weighs 4.45x10^-17 kg. Stupidly huge for a subatomic particle, stupidly tiny for a relativistic mass.
Depending how far it’s travelled, it likely has more loss from the universe expanding. Unfortunately, I can’t remember the equations for that however.
The main point is that, beyond these effects, there is no slowdown. It either flies at full speed, or hits something and creates a cascade of far slower (boring) particles.
Thanks! I learned a lot in this discussion!