SIMBAD references

Asteroid 1I/'Oumuamua is the first observed interstellar object. Its light-curve amplitude indicates that the object is highly elongated with an axial ratio of at least 5:1. The absence of such elongated asteroids in the Solar system and the apparent lack of observed interstellar objects are intriguing problems. Here we show that 'Oumuamua may have originated as a slightly elongated asteroid about 500 x 300 m in size. Surface erosion, caused by interstellar dust bombardment, subsequently increased the axial ratio. Simply travelling through the interstellar medium for 0.03 to 2 Gyr would have sufficed to give 1I its present shape. Passing through a 10 pc dust cloud with a grain density of 10^–23 g cm^–3 at 50 km s^–1 would have had a similar effect on 'Oumuamua's form. Smaller objects of around 100 m in diameter can travel the Galactic disc for merely 30 Myr before they are disrupted. This could explain the small number of interstellar objects observed to date.