In this week’s Medical Discovery News with UTMB’s David Niesel and Norbert Herzog: Researchers have learned that the high levels of radiation astronauts are exposed to while traveling in space can harm them long after they have returned to Earth. As scientists consider the prospect of a manned mission to Mars, the issue of long-term exposure poses a significant obstacle, especially now that it has been linked with Alzheimer’s disease. The column also appears in the Galveston County Daily News.