Transcript: On February 23, 1987, Oscar du Halde stepped outside his telescope to check the sky conditions at the Las Companas Observatory in Chile. He saw a new star near 30 Doradus nebula in the Large Magellanic Cloud, a small galaxy near the Milky Way. Homo sapiens were just developing on the plains of Africa a hundred and seventy thousand years ago when the blast wave from a dying star started out. The star was a blue super giant, twenty times the mass of the Sun, and as it exploded its iron plasma core collapsed from the size of Mars down to a size of about a hundred kilometers. The temperature exceeded 30 billion Kelvin, and the iron nuclei fragmented, and the explosion released a blast of neutrinos. A hundred and seventy thousand years passed; neutrinos and light traveled through space. The neutrinos arrived first, 10 billion passing through the body of every person on Earth. Delicate sensors detected the neutrinos in Japan and the United States. The light arrived a few hours later, and telescopes on Earth, on the Mir space station, and on satellite observatories focused their eyes on the dying star.