TUCSON, Arizona, June 1 (TNSjou) -- The University of Arizona issued the following news release: * * * Over 100 participants from 18 countries - including UArizona scientists and NASA's UArizona-led NEOWISE mission - took part in the international exercise. * * * Watching the skies for large asteroids that could pose a hazard to the Earth is a global endeavor. So, to test their operational readiness, the international planetary defense community will sometimes use a real asteroid's close app  more