New theory emerges for origin of cosmic rays June 11, 1998 Web posted at: 7:21 p.m. EDT (2321 GMT) SAN DIEGO (AP) -- Cosmic rays, mysterious high-energy particles that constantly zip through planets and even people, are born in the shock waves of exploding stars and sent racing outward at near the speed of light, according to a new theory. Physicists say the theory solves a puzzle of how cosmic rays can make some heavy elements, including boron, a chemical used in ordinary household soap. "If you've ever used borax, you have washed your hands in old broken up cosmic rays," Richard Lingenfelter of the University of California at San Diego said Thursday. "The boron comes from cosmic ray interactions." The new theory by Lingenfelter, Reuven Ramaty of the Goddard Space Flight Center in Maryland and Benzion Kozlovsky of Tel Aviv University in Israel was presented at the national meeting of the American Astronomical Society. Body zapped by billions of rays over lifetime Cosmic rays have puzzled astrophysicists for almost a century. It was known they bathed the universe, speeding with no apparent harm through planets, objects and people. "A dozen pass through this piece of paper every second," Lingenfelter said at a news conference. "More than 10 billion go through your body in a lifetime." The rays are nuclei of atoms, and their passage is not noticeable, although some studies have suggested that cosmic rays may break chromosomes and cause mutations. It has been suggested that such mutations over millions of years could be a factor in biological evolution. When primary cosmic rays collide with atoms of the atmosphere, they create what is called "secondary cosmic rays." Only the most energetic of these reach the ground. Primary cosmic rays have been detected using balloons and spacecraft. The rays leave marks in detectors made of plastic layers. 'Like tiny bullets' shot from a supernova? The path of cosmic rays is twisted by magnetic fields in the galaxy, making it impossible to pinpoint their origin. In 1990, it was determined that the high speed particles originate from within the Milky Way galaxy, but their exact source was unknown. Experts suggested cosmic rays were created in supernova explosions, but the precise mechanism of how the particles could be accelerated at such high rates of speed was unknown. When a supernova occurs, ionized gas is shot out into space at thousands of miles per second. It creates a powerful shock wave that moves outward at high speeds for thousands of years. In the new theory, Lingenfelter and his colleagues suggest that this shock wave is the key to cosmic rays. Lingenfelter said he believes heavy elements made by the star and sent speeding outward by its explosion condense into dust grains of graphite and metal oxides. These are shot into the cosmos "like tiny bullets," he said, and are part of an expanding high speed cloud of superheated ionized gas called plasma. Interactions create beryllium and boron The gas slows, but the grains race through the plasma. Atoms are ripped from the grains and become electrically charged. These are then accelerated to near the speed of light by the shock wave, becoming the cosmic rays, the theory states. Cosmic rays containing the nuclei of oxygen and carbon collide with interstellar matter. The collision produces beryllium, an element that uniquely is made only by cosmic rays. Later interactions create boron. Most other heavy elements are created in the nuclear fusion of stars and are spread through the universe when the star explodes. The presence of beryllium in ancient stars in the galaxy has long puzzled astronomers, but Lingenfelter said the new theory would account for the element's abundance in those stars. Lingenfelter said high-speed particles ejected from shock waves have been detected by NASA satellite instruments. Other elements of the theory will be tested by a science satellite called Advanced Composition Explorer, he said. Copyright 1998 Ê TheAssociated Press. All rights reserved. This material may Related story: Latest Headlines Scientists in Japan may NATO's mock air have discovered secret to raids over Balkans the universe's 'missing set for Monday mass' - June 5, 1998 U.N. arms chief begins talks with Related sites: Iraq India, Pakistan Note: Pages will open in a new disagree on peace browser window talks Teen guilty in Goddard Space Flight Mississippi Center school-shooting GSFC Press rampage Release 98-083 GM, UAW meet in American Flint for more Astronomical Society Home strike talks Page Byrd's friends pay What is a cosmic ray? last respects to a Scientific American: murder victim Article: Cosmic Rays at Is Intel 'dumping' the Energy Frontier: graphics chips? January 1997 ACE Home Page External sites are not endorsed by CNN Interactive. --------------------------------------------------------- CNN Programs Earth Matters Ê Ê Sunday 1:30pm - 2:00pm ET (10:30am - 11:00am PT) Science & Technology Week