Antarctica is filled with ice, penguins, and mysterious subatomic particles...among other things. Just over three years ago, physicists working on the chilly continent detected the first evidence of the particles, known as neutrinos, coming from outside our galaxy. This was huge— however, no one was able to figure out just where those particles were coming from, or why. Until now.
A team of astronomers claims that they found the source, and the story of the particles journey to us begins 10 billion years ago, when a massive explosion erupted in a far off galaxy.
But let's back up for a moment and understand why the neutrinos are such a big deal.
To begin, they're pretty strange. In fact, Science Alert describes them as "the weirdest of the fundamental subatomic particles." They don't have any mass, they're super quick, and they're basically invisible. Think: 'Wonder Woman's invisible plane,' and you'll begin to note just how weird they are.
Researchers have set up extravagant labs, like the IceCube Neutrino at the South Pole, just to detect neutrinos—which they did in 2013. They found neutrinos that were so unimaginably energetic, they knew they must have come from outside our galaxy.
Named "Bert" and "Ernie," these neutrinos were the first evidence of extragalactic neutrinos. Over the next few months, the scientists detected a couple dozen more. If you thought the Sesame Street naming spree was over, you're wrong. At the end of 2012, they spotted "Big Bird," which was the most energetic neutrino ever detected at the time.
Identifying the Culprit
Lead researcher Matthias Kadler, from the University of Würzburg in Germany, describes the hunt for the origin of these mysterious particles "like a crime scene investigation."
Well, the team believes they found the culprit: A huge explosion known as a blazar, which occurred in galaxy PKS B1424-418 around 10 billion years ago. A blazar occurs when a galaxy's material falls towards the supermassive black hole at its centre, and some of that material ends up being blasted in huge jets directly towards Earth.
"The blazar seems to have had means, motive and opportunity to fire off the Big Bird neutrino, which makes it our prime suspect," said Kadler.
The hypothesis needs to be verified before we can say for sure where Big Bird came from, but scientists are excited that we might finally be getting close to better understanding these mysterious particles.