Harvard professor Avi Loeb created a media storm in 2017 when he suggested that a cigar-shaped object passing through our solar system was created by aliens. Known as Oumuamua, this was the first object humans had ever seen from beyond our solar system.
There were many theories as to what the object was – comet, asteroid, hybrid – but Loeb stated that the object may be some kind of alien probe or alien space debris. Loeb has recently published a book in which he presents theories and evidence to support his position.
What is so intriguing about Oumuamua is that it sped up as it passed the sun and left our solar system. Asteroids slow down after traveling the same path due to the sun’s gravity.