For 15 years, scientists have benefited from data gleaned by U.S. classified satellites of natural fireball events in Earth's atmosphere - but no longer. A recent U.S. military policy decision now explicitly states that observations by hush-hush government spacecraft of incoming bolides and fireballs are classified secret and are not to be released. The satellites' main objectives include detecting nuclear bomb tests, and their characterizations of asteroids and lesser meteoroids as they crash through the atmosphere has been a byproduct data bonanza for scientists. The upshot: Space rocks that explode in the atmosphere are now classified. Scientists say not only will research into the threat from space be hampered, but public understanding of sometimes dramatic sky explosions will be diminished, perhaps leading to hype and fear of the unknown. The fireball data from military or surveillance assets have been of critical importance for assessing the impact hazard," said David Morrison, a Near Earth Object (NEO) scientist at NASA's Ames Research Center. He noted that his views are his own, not as a NASA spokesperson. "These fireball data together with astronomical observations of larger near-Earth asteroids define the nature of the impact hazard and allow rational planning to deal with this issue," Morrison said.