Publications by authors named "M Birlan"
Article Synopsis
- Telescopic observations show that asteroids often appear redder than meteorites due to a process called 'space weathering', which alters their surfaces in under a million years.
- 'Unweathered' asteroids, with spectra similar to ordinary chondrite meteorites, are primarily found in regions crossing the orbits of Mars and Earth, suggesting they have undergone recent planetary encounters.
- Research indicates that these 'Q-type' asteroids have experienced close orbital intersections within the last 500,000 years, with tidal stress being the likely cause of their fresh surfaces, helping to explain the color differences observed between asteroids and meteorites.
A comparison of the laboratory reflectance spectra of meteorites with observations of asteroids revealed that the latter are much 'redder', with the spectral difference explained by 'space weathering', though the actual processes and timescales involved have remained controversial. A recent study of young asteroid families concluded that they suffered only minimal space weathering. Here we report additional observations of those families, revealing that space weathering must be a very rapid process-the final colour of a silicate-rich asteroid is acquired shortly after its 'birth' (within 10(6) years of undergoing a catastrophic collision).
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