Government officials on Friday were reluctant to acknowledge the potential that the phenomena could be extraterrestrial craft, a signal of how unlikely they view that explanation. But both scientific experts and enthusiastic amateurs have advanced explanations ranging from the mundane to the otherworldly and the report did little to substantiate or dismiss their theories. Too little data exists to draw a conclusion about many of the episodes, officials said. The failure to reach a conclusion on the unexplained episodes raised questions about how seriously the government has taken them until now and whether it had assembled adequate scientific expertise to examine them. Government officials outlined a plan to develop, if additional funding is available, a better program to observe and collect data on future unexplained phenomena. While they clustered around military training or testing grounds, the report found that that could be the result of collection bias or the presence of cutting-edge sensors in those areas. The report said the number of sightings was too limited for a detailed pattern analysis. The nine-page document essentially declines to draw conclusions, announcing that the available reporting is “largely inconclusive” and noting that limited and inconsistent data created a challenge in evaluating the phenomena. But the government report did not rule out those explanations. There is no evidence that any of the episodes involve secret American weapons programs, unknown technology from Russia or China or extraterrestrial visitations. But, the report said, more rigorous analysis of those episodes is needed. Of those, 21 reports of unknown phenomena, involving 18 episodes, possibly demonstrate technological capabilities that are unknown to the United States: objects moving without observable propulsion or with rapid acceleration that is believed to be beyond the capabilities of Russia, China or other terrestrial nations. WASHINGTON - The government still has no explanation for nearly all of the scores of unidentified aerial phenomena reported over almost two decades and investigated by a Pentagon task force, according to a report released on Friday, a result that is likely to fuel theories of otherworldly visitations.Ī total of 143 reports gathered since 2004 remain unexplained, the document released by the Office of the Director of National Intelligence said.