Calculations by a team of astronomers at The University of Texas at Austin show that jolts of radiation from space may affect biological and atmospheric evolution on planets in our own solar system and those orbiting other stars. The work by David Smith (a former UT-Austin undergraduate, now a graduate student at Harvard University) and UT-Austin astronomers John Scalo and J. Craig Wheeler is presented today at the American Astronomical Society meeting in Washington, D.C. Bursts of radiation that can cause biological mutations, or even deliver lethal doses, can come from flares given off by the planet’s parent star or from more remote cosmic events (e.g., supernovae and gamma-ray bursts).