This artist’s impression shows the first interstellar asteroid: `Oumuamua. This unique object was discovered on 19 October 2017 by the Pan-STARRS 1 telescope in Hawai`i. Subsequent observations from ESO’s Very Large Telescope in Chile and other observatories around the world show that it was travelling through space for millions of years before its chance encounter with our star system. `Oumuamua seems to be a dark red highly-elongated metallic or rocky object, about 400 metres long, and is unlike anything normally found in the Solar System.

This is a SETI Talk on 1I/`Oumuamua on the first known interstellar small body, possibly an asteroid which is probably coming from another planetary system. Its recent discovery by Pan-STARRS1 offers a rare opportunity to explore the planetary formation processes of other stars, and the effect of the interstellar environment on a planetesimal surface. Since its discovery, astronomers around the world have raced to use the most powerful ground-based and space-borne telescopes to collect information on its nature. Two astronomers, Meg Schwamb, astronomer at the Gemini Observatory in Hawaii and Matija Cuk, astronomer at the SETI Institute in Mountain View, will discuss the nature of ‘Oumuamua, its color and shape in comparison with known small solar system bodies, as well as its origin derived from its extremely elongated shape and its orbit. They will show how its peculiarities seem to imply that ‘Oumuamua is one of the most important discoveries of the decade in astronomy.