Physical Properties
Orbit
Sources & Further Reading
- NASA — official mission / factsheet page
- Wikipedia — extensive cross-referenced article
- NASA u2014 'Oumuamua
- Meech et al., Nature 2017 u2014 A brief visit from a red and extremely elongated interstellar asteroid (2017)
Numerical values (radius, mass, orbital elements, temperatures) are drawn from NASA NSSDC Planetary Fact Sheets, JPL Horizons, and the JPL Small-Body Database. Last refreshed: 2026-04-18 18:19:28.
1I/’Oumuamua is the first confirmed interstellar object ever detected passing through the Solar System. Robert Weryk spotted it on 19 October 2017 using the Pan-STARRS 1 telescope in Hawaii. Its hyperbolic orbit (eccentricity > 1) immediately revealed that it was not gravitationally bound to the Sun and had originated outside the Solar System. ‘Oumuamua is extremely elongated — at least 6:1 axis ratio — and showed a small non-gravitational acceleration that has never been fully explained by either standard outgassing or exotic hypotheses.