Word: supernova
(lookup in dictionary)
(lookup stats)
Dates: all
Sort By: most recent first
(reverse)
...There, in the fuzzy patch of light known as the Large Magellanic Cloud, was the spot. Says Shelton: "For more than three hours, I tried several logical explanations. It took me a long time to actually accept that what I had just seen was a supernova...
...supernova it was, a massive star dying in an explosion so violent that for a few weeks it will outshine hundreds of millions of stars put together. Its home, the Large Magellanic Cloud, is a satellite galaxy, or island of stars, that lies just beyond the fringes of our Milky Way galaxy, some 170,000 light-years from earth. (A light-year, the distance light travels in a year, is roughly 6 trillion miles...
...black hole is believed to be the stellar remnant formed by the supernova explosion of a star. When the star's outer shell is blown away, the heavier elements of the core collapse upon themselves. This collapsing mass is then compacted by gravity into a mere point from which nothing, not even light, can escape...
...team knew of only a few places where such high concentrations of the rare element might occur: in the earth's core, perhaps 2,000 miles belowground; in extraterrestrial objects like asteroids (or their fragments, meteors) and comets; or in the cosmic dust drifting to earth from a nearby supernova (exploding star). The core material seemed too deep to come to the surface, and further analysis ruled out a supernova as the source, so father and son concluded that the iridium had been left by a giant asteroid hitting the earth at the end of the Cretaceous period...
...cosmic rays of a nearby supernova may have caused the extinction of the dinosaurs," he says. But, he adds, there are currently no stars close enough to place the planet in danger...