The first object in history to pass through the solar system and to be identified as originating outside the solar system was discovered in October 2017 by Canadian astronomer Robert Weryk in Hawaii. The object was named Oumuamua, which in Hawaiian means first distant messenger. Avi Loeb, the chairman of the astronomy department at Harvard believes that the object, which passed Earth at a distance of 24 million kilometres on an extreme hyperbolic orbit, displays signs of solar sail technology. He posits that it could be a long lost probe from a distant civilisation. NASA believes the particular propulsion pattern was caused by gas emissions.