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Updated: Feb 18, 2026
11:34
Scattering And Absorption of Light in Planetary Regoliths
Published on: July 1, 2019
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A brief visit from a red and extremely elongated interstellar asteroid
Karen J Meech1, Robert Weryk1, Marco Micheli2,3
1Institute for Astronomy, 2680 Woodlawn Drive, Honolulu, Hawaii 96822, USA.
Nature
|November 22, 2017
Summary
The first detected interstellar object,
Area of Science:
- Astronomy and Astrophysics
- Planetary Science
Background:
- Solar System formation models predict ejection of planetesimals into interstellar space.
- Previous searches have not detected interstellar objects, despite predicted number densities.
- No method existed to compare Solar System materials with those from other planetary systems.
Purpose of the Study:
- To confirm the extrasolar origin of the object 1I/2017 U1 ('Oumuamua).
- To enable comparative analysis of materials from different planetary systems.
- To assess the abundance and characteristics of interstellar objects.
Main Methods:
- Analysis of trajectory to determine extrasolar origin.
- Spectroscopic measurements of surface composition.
- Light-curve observations to determine shape and size.
Main Results:
- Confirmed 'Oumuamua's trajectory as extrasolar.
- 'Oumuamua exhibited asteroidal characteristics with no cometary activity.
- Spectrally red surface, extremely oblong shape (10:1 length-to-width ratio), and estimated radius of 102m.
- Object's dimensions are unprecedented among known Solar System objects.
Conclusions:
- The detection of 'Oumuamua confirms the existence of interstellar objects.
- Previous estimates of interstellar object number density may be underestimated.
- 'Oumuamua provides a unique opportunity to study materials from another planetary system.
- Future surveys with enhanced instruments will likely detect more interstellar objects.
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