On October 19, 2017, Scientists detected the first known alien visitor, named Oumuamua, passing through our Solar System. It was about 33 million km from Earth (about 85 times as far away as the Moon), and already heading away from the Sun. The interstellar object was relatively flat and cigar-shaped. Astonomers aren’t exactly sure where it came from, or really even what it is. However, in July 2019, astronomers reported that Oumuamua was an object of a purely natural origin. (Oumuamua in Hawaiian means “scout” or “visitor from after arriving first”.)
The Spitzer Space Telescope did not detect any heat in the form of infrared radiation from ‘Oumuamua. Given the surface temperature dictated by ‘Oumuamua’s trajectory near the sun, this sets an upper limit on its size of hundreds of meters. Based on this size limit, ‘Oumuamua must be unusually shiny, with a reflectance that is at least 10 times higher than exhibited by solar system asteroids.
Picture Credit : Google