Supernova Neutrinos
Every second, trillions of tiny particles zip through your body -- and you'll never feel a thing. The particles are neutrinos, and they're produced in vast amounts by the nuclear reactions inside the Sun. But these ghostly particles have almost no mass, and they almost never interact with other forms of matter. As a result, they race through a star, a planet, or even a person without slowing down. Even so, neutrinos are one of the key forces behind the exploding stars known as supernovae.
A supernova explosion begins when the core of a heavy star collapses. All the space is squeezed out of the core's atoms, and its protons and electrons are squeezed together to form neutrons. That produces a small, superdense object called a neutron star.
It also produces an incredible torrent of neutrinos. When a supernova was seen in a nearby galaxy in 1987, astronomers calculated that it produced 10 to the 59th neutrinos -- a one followed by 59 zeroes.
When the core collapses, the star's hot outer layers fall toward the neutron star, then rebound. That creates a shockwave that begins to travel through the star. Even though neutrinos seldom interact with other matter, a collapsing star produces so many of them that they provide most of the "kick" to push the shockwave through the entire star.
But neutrinos probably can't do it all on their own -- they need something else to finish the job. More about that tomorrow.
Script by Damond Benningfield, Copyright 2006
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