What exactly is Oumuamua, is it an asteroid, a comet or even maybe an interstellar spaceship? One thing is for sure, it does not originate from the solar system. Initially, it as been cataloged as 1I/2017 U1 by the International Astronomical Union (IAU) and then baptized Oumuamua by the Pan-STARRS team who discovered the mysterious object. The discovery was made on October 19, 2017, by the University of Hawaii’s Pan-STARRS1 telescope, which is funded by NASA and is part of the Near-Earth Object Observation (NEOO) program.
Early on, scientists thought it was a comet, but as it made its close approach to the sun, the lack of cometary activity lead the scientist to reclassified the object as an asteroid. Shortly after its close encounter with the Sun, new observation showed that it was accelerating thus behaving like a comet, which really baffled scientists. Some further measurements revealed that Oumuamua had a hyperbolic orbit indicating that it came from a different system than ours. Astronomers had already considered the possibility of interstellar bodies, such as asteroids and comets, passing through the solar system, and they said that it was probably a common thing as well. Since the discovery of Oumuamua, we now have the confirmation that some interstellar objects wander through our solar system.
But what if 1I/2017 U1 was not a comet or an asteroid but an artificial object like an exploration probe or an interstellar ship. It is impossible to say but here are a few interesting facts about Oumuamua. First of all, its cigar-shape, with approximately 400 meters long and 40 meters wide, vaguely resembles the shape of our rockets. Furthermore, its ten to one length/width ratio is much greater than any bodies we have observed in our solar system. Also, this odd-shaped object seems to have made a slingshot maneuver, using our star to accelerate, exactly as we do with our probes using planets to gain more speed. Finally, its got a reddish hue which indicates a metal-rich composition that’s been exposed to cosmic radiations. That could mean a metal structure that turned red after spending a tremendous amount of time in space traveling from star to star. Maybe they entered our solar system only to use our Sun to accelerate their ship or maybe it was a probe on a survey mission, but unfortunately, we will never know because Oumuamua is too far now for us to study it more.
Even if the idea of an alien spaceship could be possible, scientist debunked that possibility and said that Oumuamua was most likely a planetesimal fragment that has been expulsed out of its orbit during the formation of planets in a distant system and that it drifted through space for hundreds of millions of years before it entered our solar system.