Asteroid collisions in the main belt eject fragments that may eventually land on Earth as meteorites1,2,3. It has therefore been a long-standing puzzle in planetary science that laboratory spectra of the most populous class of meteorite (ordinary chondrites, OC) do not match the remotely observed surface spectra of their presumed (S-complex) asteroidal parent bodies. One of the proposed solutions to this perplexing observation is that ‘space weathering’ modifies the exposed planetary surfaces over time through a variety of processes (such as solar and cosmic ray bombardment, micro-meteorite bombardment, and so on). Space weathering has been observed on lunar samples4, in Earth-based laboratory experiments5,6, and there is good evidence from spacecraft data that the process is active on asteroid surfaces7,8. Here, we present a measurement of the rate of space weathering on S-complex main-belt asteroids using a relationship between the ages of asteroid families and their colours9. Extrapolating this age–colour relationship to very young ages yields a good match to the colour of freshly cut OC meteorite samples, lending strong support to a genetic relationship between them and the S-complex asteroids.
Subscribe to Journal
Get full journal access for 1 year
only $3.90 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Tax calculation will be finalised during checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
Vokrouhlický, D. & Farinella, P. Efficient delivery of meteorites to the Earth from a wide range of asteroid parent bodies. Nature 407, 606–608 (2000)
Gladman, B. J. et al. Dynamical lifetimes of objects injected into asteroid belt resonances. Science 277, 197–201 (1997)
Wisdom, J. Meteorites may follow a chaotic route to earth. Nature 315, 731–733 (1985)
Adams, J. B. & McCord, T. B. Alteration of lunar optical properties: Age and composition effects. Science 171, 567–571 (1971)
Moroz, L. V., Fisenko, A. V., Semjonova, L. F., Pieters, C. M. & Korotaeva, N. N. Optical effects of regolith processes on S-asteroids as simulated by laser shots on ordinary chondrite and other mafic materials. Icarus 122, 366–382 (1996)
Sasaki, S., Nakamura, K., Hamabe, Y., Kurahashi, E. & Hiroi, T. Production of iron nanoparticles by laser irradiation in a simulation of lunar-like space weathering. Nature 410, 555–557 (2001)
Chapman, C. R. S-type asteroids, ordinary chondrites, and space weathering: The evidence from Galileo's fly-bys of Gaspra and Ida. Meteorit. Planet. Sci. 31, 699–725 (1996)
Clark, B. E. et al. Space weathering on Eros: Constraints from albedo and spectral measurements of Psyche crater. Meteorit. Planet. Sci. 36, 1617–1637 (2001)
Ivezić, Ž., Jurić, M., Lupton, R. H., Tabachnik, S. & Quinn, T. in Survey and Other Telescope Technologies and Discoveries (eds Tyson, J. A. & Wolff, S.) Vol. 4836, 98–103 Proc. SPIE (2002)
Hapke, B. Space weathering from Mercury to the asteroid belt. J. Geophys. Res. 106, 10039–10074 (2001)
Michel, P., Benz, W., Tanga, P. & Richardson, D. C. Collisions and gravitational reaccumulation: Forming asteroid families and satellites. Science 294, 1696–1700 (2001)
Milani, A. & Knežević, Z. Asteroid proper elements and the dynamical structure of the asteroid main belt. Icarus 107, 219–254 (1994)
Gaffey, M. J. et al. Mineralogical variations within the S-type asteroid class. Icarus 106, 573–602 (1993)
Doressoundiram, A., Barucci, M. A., Fulchignoni, M. & Florczak, M. EOS family: A spectroscopic study. Icarus 131, 15–31 (1998)
Deeming, T. J. Stellar spectral classification, I. Mon. Not. R. Astron. Soc. 127, 493–516 (1964)
Ivezić, Ž. et al. Color confirmation of asteroid families. Astron. J. 124, 2943–2948 (2002)
Tedesco, E. F., Noah, P. V., Noah, M. & Price, S. D. The supplemental IRAS minor planet survey. Astron. J. 123, 1056–1085 (2002)
Sykes, M. V. et al. The 2MASS asteroid and comet survey. Icarus 146, 161–175 (2000)
Bus, S. J. & Binzel, R. P. Phase II of the small main-belt asteroid spectroscopic survey. Icarus 158, 106–145 (2002)
Migliorini, F. et al. Surface properties of (6) Hebe: A possible parent body of ordinary chondrites. Icarus 128, 104–113 (1997)
Morbidelli, A. & Vokrouhlický, D. The Yarkovsky-driven origin of near-Earth asteroids. Icarus 163, 120–134 (2003)
Marti, K. & Graf, T. Cosmic-ray exposure history of ordinary chondrites. Annu. Rev. Earth Planet. Sci. 20, 221–243 (1992)
Binzel, R. P., Bus, S. J., Burbine, T. H. & Sunshine, J. M. Spectral properties of near-Earth asteroids: evidence for sources of ordinary chondrite meteorites. Science 273, 946–948 (1996)
Rabinowitz, D. L. Size and orbit dependent trends in the reflectance colours of earth-approaching asteroids. Icarus 134, 342–346 (1998)
di Martino, M., Manara, A. & Migliorini, F. 1993 VW: an ordinary chondrite-like near-Earth asteroid. Astron. Astrophys. 302, 609–612 (1995)
Lazzarin, M., di Martino, M., Barucci, M. A., Doressoundiram, A. & Florczak, M. Compositional properties of near-Earth asteroids: spectroscopic comparison with ordinary chondrite meteorites. Astron. Astrophys. 327, 388–391 (1997)
Gaffey, M. J. Spectral reflectance characteristics of the meteorite classes. J. Geophys. Res. 81, 905–920 (1976)
We thank C. Chapman and J. Taylor for providing background on the S-complex conundrum and B. Clark for useful discussions and further studies. D.N. thanks NASA PG&G and the SwRI Quicklook programmes for providing support. Funding for the creation and distribution of the SDSS Archive has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Aeronautics and Space Administration, the National Science Foundation, the US Department of Energy, the Japanese Monbukagakusho, and the Max Planck Society. The SDSS website is http://www.sdss.org/.
The authors declare that they have no competing financial interests.
Contains Supplementary Table 1 giving the ages and colours of S-complex asteroids as well as two methods sections summarizing the techniques used for asteroid family identification and age determination. (DOC 60 kb)
About this article
Cite this article
Jedicke, R., Nesvorný, D., Whiteley, R. et al. An age–colour relationship for main-belt S-complex asteroids. Nature 429, 275–277 (2004). https://doi.org/10.1038/nature02578