Mysterious 'Oumuamua Object Still Defies Explanation 5 Years After Discovery It's been five years since astronomers detected the first known interstellar object, 'Oumuamua, hurtling through our solar system. Since its discovery in 2017, scientists have been baffled by the object's unusual shape, size, and composition, sparking intense debate over its origins and purpose. Researchers have proposed a range of theories, from a fragment of a disintegrated star to an alien spacecraft, but none have been proven conclusively. As new data and research continue to emerge, scientists are still struggling to unlock the secrets of this enigmatic interloper.