A Mysterious 'Oumuamua Object Has Been Spotted in the Outer Reaches of Our Solar System A bizarre and unexplained object, dubbed 'Oumuamua, has been detected in the outer reaches of our solar system, sending shockwaves through the scientific community. This interstellar visitor, measuring around 400 meters in length, was first spotted in October 2017 and has been the subject of intense scrutiny and debate ever since. While its exact nature remains a mystery, astronomers have proposed a range of theories, from a rogue asteroid to an alien spacecraft. As scientists continue to study 'Oumuamua, they may uncover secrets about the universe and its many unexplained phenomena.