» A Harvard professor has claimed in his new book that alien debris passed near Earth in 2017. It has attracted both skepticism and intrigue. A Harvard professor has claimed in his new book that alien debris passed near Earth in 2017. It has attracted both skepticism and intrigue. Kevin ShalveyJan 3, 2021, 19:48 IST This artist's impression shows the first-known interstellar object to visit the solar system, "Oumuamua," which was discovered on October 19, 2017, by the Pan-STARRS1 telescope in Hawaii.European Southern Observatory/M. Kornmesser/Handout via Reuters Scientists in 2017 detected t...