Artist’s impression of the 400-meter-long interstellar asteroid 1I/2017 U1 `Oumuamua. Credit: ESO/M. Kornmesser.
Remember that comet-no-wait-asteroid astronomers discovered in October on a high-velocity hyperbolic orbit around the Sun? It has been determined that the object must be of interstellar origin and, based on follow-up observations over the past several weeks, it’s shaped like nothing that’s ever been seen before.
First designated C/2017 U1 PanSTARRS (due to its discovery with the Pan-STARRS 1 telescope in Hawaii) the object’s name was shortly afterward changed to A/2017 U1 and now it’s been given the designation 1I/2017 U1 `Oumuamua — “I” indicating an interstellar origin and `Oumuamua being from the Hawaiian words for “first outreach,” in this instance to us from another star system!
Animation of the hyperbolic path of the interstellar asteroid `Oumuamua. It made its closest approach to the Sun on Sept. 19, 2017. (NASA)
`Oumuamua is also the first object to receive an interstellar designation by the IAU.
Spectral and light-curve observations have revealed that `Oumuamua is reddish in color—similar to Kuiper Belt Objects and the trojan asteroids that orbit the Sun along with Jupiter—indicating an ancient surface turned dark through long exposure to UV radiation, a rocky or metallic composition ...