Star Explosion Sends Chemical Elements Flying Through Space
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National Aeronautics and Space Administration Star Explosion Sends Chemical Elements Flying Through Space www.nasa.gov Except on For the classroom: Earth, the got calcium? Milky Way How much calcium is in Cassiopeia A? galaxy doesn’t contain any milk. But it sure does have a lot of calcium. There’s enough Use the following information to find out: calcium floating between the stars to fortify trillions upon trillions of gallons of milk. • The star that produced the supernova remnant Cassiopeia A was about 20 times Calcium comes from stars. In fact, all of more massive than the Sun. It was largely the elements that make up your body and made up of hydrogen but also contained the planet Earth itself, other than hydrogen some calcium and other elements. and helium, were made in stars or during Visble light image of Cas- explosions of massive stars. siopeia A (from a tele- • When the star exploded, the calcium and scope on Earth) other elements produced by fusion during Stars are like mighty atomic factories. They the life of the star fly off into space. The combine hydrogen and helium through a explosion creates more of these and other process of nuclear fusion, which produces elements. The total amount of calcium is a tremendous amount of heat energy. In equal to about 0.05% of the mass of the addition to energy, the fusion process in original star. massive stars (stars having more than 8 times the mass of our sun) results in carbon, • One glass of milk (8 fluid oz. or 237 nitrogen, iron and other atoms. As iron ml) contains approximately 300 mg of accumulates in the stellar core, the fusion calcium. process no longer produces heat energy. At this point in the life of a massive star, Using this information, the core collapses and the star explodes, X-ray image of Cassiopeia sending all those atoms racing into space. A (from Chandra X-ray 1) How many kilograms of calcium are Some atoms bump into each other in the Observatory) in a typical supernova remnant, like fury, fusing to create even heavier atoms Cassiopeia A? such as gold, silver and uranium. These 2) How many 8-ounce glasses of milk atoms spread across the galaxy over the would this equal? course of billions of years. 3) How long must the cows in the United States be milked to produce this Cassiopeia A is a star that exploded about number of glasses of milk? 320 years ago. No astronomer recorded the explosion at the time, but we can still For the answer to the “For the Classroom” see the remains of the explosion today in questions, see: the form of a colorful supernova remnant. http://imagine.gsfc.nasa.gov/docs/ By measuring the motion of the gas in the teachers/calcium/ remnant, astronomers deduce its age. X-ray image showing only The Michigan-Dartmouth-Massachusetts the calcuium present in For more information on supernovae and Cassiopeia A (also from supernova remnants, see: Institute of Technology Observatory on Kitt Chandra X-ray Observa- Peak, Arizona, captured a beautiful image tory) http://imagine.gsfc.nasa.gov/ of Cassiopeia A in visible light (above, top). In an image accumulated over a million http://chandra.harvard.edu/xray_sources/ seconds, the Chandra X-ray Observatory, supernovas.html an earth-orbiting satellite, saw the hot X- ray-emitting gas from the explosion (on For more information about how stars make front, and middle image, this page). This elements through fusion, see: gas is hotter than the surface of the sun. http://imagine.gsfc.nasa.gov/docs/ Chandra was also able to see the individual teachers/elements/ elements within the explosion. For example, researchers at NASA’s Goddard Space Flight Center created an image showing only the element calcium (bottom image). LG-2002-3-041-GSFC .