U.S. — Astronomer Avi Loeb just published a new book in which he doubles down on his controversial claim that interstellar object Oumuamua could have been an alien craft.
Here's what you need to know: Oumuamua is the first interstellar object ever observed by humans.
It was discovered on 19 October 2017, when it was about 33 million kilometers from Earth, and already heading away from Earth.
Scientists were unable to get a clear picture of how the object looked, but estimate it is roughly a cigar-shaped object that entered the solar system at an unusual orbit and unusually high speed.
Researchers found it hard to determine some of the phenomena displayed by the object.
One scientist, Avi Loeb, published an article in 2018 stating that the object could be a light sail or probe sent intentionally to Earth's vicinity by an alien civilization.
Other astro-physicists were not impressed.
In 2019, an international team of researchers published a study and said they found that "Oumuamua's properties are consistent with a natural origin." But Loeb replied in 2020 that the data we gathered on Oumuamua is incomplete.
He added that "to learn more, we must continue to monitor the sky for similar objects." According to Forbes magazine, Loeb's new book doubles down on his claim that the object could have been an alien craft.