Science/Medicine : Gamma Rays From Big Supernova Detected

Scientists say they detected gamma rays from a giant supernova, confirming a long-held theory that all the heavy elements in the universe were produced by such ancient exploding stars.

“Earth is the way it is because it was formed out of material ejected by some earlier supernova,” said astrophysicist Tom Prince, of Caltech in Pasadena. “Just about everything we see around us--such as the iron in your car--was thrown out from a supernova.”

“We wouldn’t have life as we know it without the production of these heavy elements (such as nickel, cobalt and iron) in supernovas,” said astrophysicist Gerald Share of the Naval Research Laboratory in Washington. “We wouldn’t have cars. It would be very hard to build tall buildings because there wouldn’t be steel beams.”

And without iron in Earth’s core, the planet would lack the magnetic field that “protects us from being destroyed by radiation” from space, Share said.

The discovery that Supernova 1987A emits gamma rays, similar to radiation used to treat cancer patients, was revealed over the last nine days by three teams of scientists working for a NASA program aimed at studying the exploding star about 160,000 light years, or 1 million trillion miles, from Earth.

The gamma rays, detected by instruments aboard a satellite and two balloons, are emitted when radioactive cobalt-56 in Supernova 1987A changes into iron.