Here comes the sun, and its zillions of neutrinos.
Physicists have finally detected the neutrinos sent out by the sun, giving us a glimpse into how the star burns.
The study by some scientists at the University of Massachusetts Amherst found these neutrinos by finding the proton-proton fusion process occurring at the sun's core, the reaction that causes 99 percent of the power the sun shines out.
They have measured the neutrinos being emitted by the sun and found that up to 420 billions of neutrinos hit each square inch of our world, travelling at the speed of light. It takes eight minutes for these neutrinos to travel through the almost 93 million miles of space to reach us. According to the study, it actually takes tens of thousands of years for these neutrinos to move from the heart of the sun to the surface.
"By comparing the two different types of solar energy radiated, as neutrinos and as surface light, we obtain experimental information about the Sun's thermodynamic equilibrium over about a 100,000-year timescale," stated Andrea Pocar, who led the study, in a statement. "If the eyes are the mirror of the soul, with these neutrinos, we are looking not just at its face, but directly into its core. We have glimpsed the sun's soul."
To measure the neutrinos, the scientists used the Borexino detector, which lays beneath Italy's Apennine Mountains. It can detect neutrinos as they effect the electrons of a liquid scintillator at the center of a sphere surrounded by 1,000 tons of water. The depth and onion-like protective layers make that core the most radiation-free place on the planet so the radiation decay from neutrinos can be measured versus the many minor radiation occurrences that happen on the Earth's surface.
Detecting the sun's neutrinos was not part of the original Borexino experiment. "It's a little bit of a coup that we could do it. We pushed the detector sensitivity to a limit that has never been achieved before," said Pocar.
The study was published in the journal Nature, in an article called, "Neutrinos from the primary proton-proton fusion process in the Sun."
Photo: Marsel Minga / Flickr