Forskare: Mystisk asteroid kom från annat solsystem

ʻOumuamua ( pronunciation ; formally designated 1I/ʻOumuamua; previously C/2017 U1 (PANSTARRS) and A/2017 U1) is an interstellar object passing through the Solar System. It was discovered on a highly hyperbolic trajectory by Robert Weryk on October 19, 2017, with observations made by the Pan-STARRS telescope when the object was 0.2 AU (30,000,000 km; 19,000,000 mi) from Earth. Initially thought to be a comet, it was reclassified as an asteroid a week later. It is the first of a new class called hyperbolic asteroids. As a result of its strong hyperbolic trajectory, it will exit the Solar System in roughly 20,000 years. Based on a 29-day observation arc, ʻOumuamua's orbital eccentricity is 1.20, the highest of any object yet observed in the Solar System. The previous record holder was C/1980 E1 with an outbound-orbit eccentricity of 1.057. The high eccentricity of ʻOumuamua both inbound and outbound indicates that it has never been gravitationally bound to the Solar System and is an interstellar object due to its high incoming velocity. It has an inclination of 123° with respect to the ecliptic, and had a speed of 26.33 km/s (58,900 mph) relative to the Sun when in interstellar space, which peaked at 87.71 km/s (196,200 mph) at perihelion.