Appropriately named after the Hawaiian word meaning “a messenger from afar arriving first,” ‘Oumuamua is the first known interstellar object ever observed, and it’s quite an interesting (not so) little rock. It was discovered on October 19, 2017 when astronomers at the University of Hawaii working on Pan-STARRS1 noticed an object traveling at high speeds across our solar system, escaping the gravitational pull of our Sun, thrusting itself on a trajectory to leave our solar system. It is about 230 by 35 meters, and is dark red in color. Speculated to have been ejected from a distant star system, its existence in our solar neighborhood has allowed researchers a new perspective on how planetary systems develop, along with some interesting theories on where it came from.

In a paper published on November 12, 2018 in the Astophysical Journal Letters titled “Could Solar Radiation Pressure Explain ‘Oumuamua’s Peculiar Acceleration?’, a pair of Harvard researchers suggest “a more exotic scenario is that ‘Oumauamua may be a fully operational probe sent intentionally to Earth vicinity by an alien civilization.”

The Object’s presumed density, odd trajectory, sudden acceleration and the way it rotates unlike any other asteroid known to exist, leads researchers Shmuek Bialy and Abraham Loeb to this possibility and several others including that the object is a lightsail similar to those designed on Earth (IKAROS Project and the Starshot Initiative). They summarize that utilizing solar radiation pressure, although the object is thin, it is capable of traveling galactic distances while maintaining its momentum and unaffected by collisional destruction.


As of July 2018 ‘Oumuamua is no longer visible to telescopes.  Its origin and amount of time spent sailing the stars remains unknown. Researchers hope that using the Large Synoptic Survey Telescope (LSST) to perform deep wide-area surveys will lead to the discovery of additional ‘Oumuamua-like objects for further investigating. If the object originated with a random trajectory, the numbers suggest that there may be many of these pancake like rocks (extremely oblate spheroids) floating out in the Cosmos. However, if one assumes ‘Oumuamua arrived in our solar system as a targeted probe, this discrepancy is resolved. So far, it’s the only one of its kind we got. Perhaps one day, studying this phenomenon may lead to our own civilization’s development of interstellar travel technology.