Space is unbelievably large and mysterious. It is unlikely that we will completely explore it before the end of humanity. Every once in a while, we discover some mysterious celestial body or observe some unexplainable anomalies.
We rarely have answers to these mysteries. All we do is brainstorm over what they could or could not be. Nevertheless, some are so weird that we have considered them as evidence of the existence of some intelligent life out there.
In October 2017, astronomers detected a mysterious object floating through our solar system. They named it Oumuamua. It flew close to the Sun—reaching one-fourth the distance between the Sun and the Earth—before suddenly accelerating and escaping from our solar system.
Astronomers do not know what Oumuamua is or the cause of its sudden acceleration. Some astronomers have suggested that it is an abnormal comet. Others think it is an asteroid, a less than fully formed planet, a solar sail, or a large body of ice that broke off from a destroyed planet.
Shmuel Bialy and Avi Loeb of Harvard University suspect that Oumuamua is a solar sail, which is a solar-powered spacecraft. Bialy and Loeb think that the sail was built by aliens to explore our solar system.
However, other astronomers disagree. Zdenek Sekanina of NASA believes that Oumuamua is an icy comet without a tail. He suggested that Oumuamua lost the water and gases that would have formed its tail when it strayed too close to the Sun.
Gregory Laughlin and his team at Yale University agree that Oumuamua is made of ice even though they do not think it is a comet. They believe that it used to be part of an icy planet that was destroyed after straying close to a larger planet.
Amaya Moro-Martin of the Space Telescope Science Institute thinks that Oumuamua is the remnant of a partly formed planet. He and his team suspect that the planet was still forming at the time it was flung out of its star system. If this is true, Oumuamua is the first less than fully formed planet we have found.