1st-ever interstellar object probably a comet: Astronomers
'Oumuamua, the first interstellar object to visit the Solar System, is being reconsidered as a comet after being thought as comet and then classified as asteroid. Fresh observations revealed a carbon-rich coating, formed when organic ices of carbon dioxide and methane are burnt in cosmic radiation. It could explain why 'Oumuamua didn't emit comet-like gas and dust clouds, said astronomers.