The National Science Foundation has announced that the world’s strangest telescope is complete. Unlike conventional optical or radio telescopes, this new observatory built at the bottom of the world will capture and analyze one of the most elusive particles in the universe: the neutrino.
Neutrinos are kicked out of the heart of stars. Scientists theorize that most—if not all—of these tiny particles were created during the first fractions of a second after the Big Bang.
Ghost particles
The properties of neutrinos are unique; they permit astronomers a glimpse deep into the workings of stars and allow them to “see” beyond the murky gases and dust clouds that drift within certain regions of space.
Neutrinos are like ghost particles; unlike other particles like protons and electrons, neutrinos hold no charge. They’re detected only upon a collision with the nucleus of an atom.
Those events are rare and random. Nailing down the ghost particle takes persistence, patience and a bit of faith.
Many years after theoretical physicists first postulated the existence of the sub-atomic particle, some astronomers dismissed the idea of neutrinos as mere fantasy.
The particles rarely interact with matter and most pass through the Earth avoiding a collision with anything. According to mathematicians, billions of neutrinos could pass through a dense substance like lead with no measurable detection. In fact, if a mass of lead a light year thick was set drifting off into space, uncounted trillions of the ghostly particles would zip right through it never meeting up with any lead atom.
While the properties of neutrinos themselves are amazing, the reason research on them has intensified is because they are the one particle that holds the promise of solving the mysteries of dark matter (and perhaps dark energy, if it exists).
Only four percent of the universe is visible—the other 96 percent is “dark.” No one really knows what the dark matter is, where it came from or what its properties are within the universe. Astrophysicists believe that neutrinos may help resolve those questions about dark matter.
The Ice Cube
Sunk into some of the deepest holes on the planet, the neutrino telescope is called “Ice Cube.” For an astronomical device operating in the depths of the Antarctic it’s an appropriate name.
Built to endure the savage South Pole winters, Ice Cube has its primary sensors buried deep under the icecap. It’s assumed that the sensor arrays will be frozen for centuries. The deep holes were made with high pressure jets of super-heated water.
When a neutrino happens to collide with an atom encased in ice, a sub-atomic particle—a muon—is catapulted away from the collision. The muon travels almost at the speed of light. Because of the physical principles involved, the speed of light is measurable slower in ice. It is no longer traveling at 186,000 miles per second.
Faster-than-light events
The Ice Cube telescope takes advantage of this fact. When a particle is traveling faster than the slowed down speed of light in ice an intense blue spark is created during a neutrino collision. That tiny flash of light—Cherenkov radiation—allows scientists to measure the event and calculate the trajectory of the neutrino that produced it. By taking into account the intensity of the collision, the angle and duration of the event, they can find where the neutrino originated from…what part of space, even the star that ejected it.
The sensor array is comprised of 4,800 detectors under the ice. Each can detect and record data about Cherenkov radiation events. Sixty detectors are sunk into each of eighty holes.
The telescope complex is near the major Antarctic research station, Amundsen-Scott Station.
