interstellar object passing through the Solar System, discovered in October 2017

ʻOumuamua (Hawaiian: first messenger arriving from afar)[1] is an object from another star system that visited our solar system. Its official name is 1I/2017 U1.

ʻOumuamua is the first interstellar object that we know has passed through our solar system.[2] Oumuamua was first discovered on 19 October 2017 using the Pan-STARRS1 telescope at the Haleakala Observatory in Hawaii.[3]

Its appearance is long and narrow, and it had a dark red color, similar to objects in the outer Solar System.


  1. Gareth V. Williams (November 6, 2017). "MPEC 2017-V17: New Designation Scheme for Interstellar Objects". minorplanetcenter.net.
  2. Karen Northon (June 27, 2018). "Our Solar System's first known interstellar object gets unexpected speed boost". nasa.gov.
  3. Karen J. Meech; et al. (November 1, 2017). "Discovery and characterization of the first known interstellar object" (PDF). Nature.