That's the word this week from astronomers who have been observing this first-ever confirmed interstellar visitor.
Scientists are certain this 600-foot-long, pale pink asteroid or comet originated outside our solar system. First spotted last month, it will stick around for another few years before departing our sun's neighborhood.
The International Astronomical Union, meanwhile, has approved a new designation for cosmic interlopers like this one. They get an "I'' for interstellar in their string of letters and numbers. The group has also approved a name for this object: Oumuamua, which in Hawaiian means a messenger from afar arriving first.
The Pan-STARRS telescope in Hawaii made the discovery in mid-October.