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The Earth's secret companion

Nature volume 387, pages 651–652 (1997)Cite this article

The Earth has a second companion — an asteroid, about 5 km across, in a peculiar type of orbital resonance called an overlapping horseshoe. It is probably only a temporary liaison.

Although sharing an orbit with a planet may seem an unlikely way for an asteroid to avoid collisions, being placed at the eye of the dynamical storm does offer some form of protection. The discovery by Wiegert et al. (see page 685of this issue1) that the unnamed asteroid 3753 shares its orbit with the Earth is the latest and most unusual example of a co-orbital resonant configuration that has been known for more than two hundred years.

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Figure 1: Three resonant orbits in a Sun-planet system, shown in a frame rotating with the planet's orbit.

References

  1. Wiegert, P. A., Innanen, K. A. & Mikkola, S. Nature 387, 685–686 (1997).

    Article  ADS  CAS  Google Scholar 

  2. Mikkola, S., Innanen, K. A., Muinonen, K. & Bowell, E. Celest. Mech. Dyn. Astron. 58, 53–64 (1993).

    Google Scholar 

  3. Nicholson, P. D. et al. Icarus 100, 464–484 (1992).

    Google Scholar 

  4. Bottke, W. F. et al. in Hazards due to Comets and Asteroids (ed. Gehrels, T.) 337-357 (Univ. Arizona Press, Tucson, 1994).

  5. de la Barre, C. M., Kaula, W. M. & Varadi, F. Icarus 121, 88–113 (1996).

    Google Scholar 

  6. Dermott, S. F., Gold, T. & Sinclair, A. T. Astron. J. 84, 1225–1234 (1979).

    Google Scholar 

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  1. Astronomy Unit, Queen Mary and Westfield College, E1 4NS, London, UK

    Carl D. Murray

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  1. Carl D. Murray
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Murray, C. The Earth's secret companion. Nature 387, 651–652 (1997). https://doi.org/10.1038/42585

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