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P-type asteroidA fairly common main-belt asteroid type with an orbital distribution that peaks near the 3:2 orbital resonance with Jupiter, at a semimajor axis length of 4.0 AU. (An asteroid here will orbit three times for every two orbits of Jupiter.) These asteroids have featureless spectra and low albedos. Their surfaces are thought to be rich in organic material.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006