Ever since astronomers identified the object Oumuamua in 2017, traveling at more than 90,000 kilometers per hour in the Solar System, it has been speculated that it originated in some other planetary system. One of the most controversial hypotheses was raised by Avi Loeb and Amir Siraj, renowned astronomers at Harvard University. The duo believe the mysterious space traveler may be an alien spacecraft.
Oumuamua: Extraterrestrial Technology?
The first observations of Oumuamua indicated that its orbit was too eccentric and its speed extremely high to be an object originating in the Solar System. At first it was believed to be a comet, but this theory was discarded as it showed no signs of sublimation or evaporation, which causes comets to have a characteristic tail that always points away from the Sun.
Earlier this year, Alan Jackson and Steven Desch, astronomers at Arizona State University, published two surveys on Oumuamua. Unlike Loeb and SIraj, they claim the object is “probably a chunk of nitrogen ice that broke off from a Pluto-like planet somewhere outside our Solar System.” They explain that as “Oumuamua approached the Sun, the evaporation of nitrogen gas would have pushed the object – which occurs with comets – and this would have been invisible to telescopes.
Loeb and Siraj called what Jackson and Desch said “impossible”, strongly criticizing the calculations employed by their colleagues. They maintained that nitrogen is a rare and very scarce element, and that there is not enough of it in the universe to generate a body of the enormous dimensions of Oumuamua. Siraj insists that it is not possible to rule out so quickly the possibility that the object has an artificial origin.