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.