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SUMMARY:Exchange of debris between planetary systems - Moro-Martin\, A (Ma
 drid)
DTSTART:20090821T094000Z
DTEND:20090821T100000Z
UID:TALK19491@talks.cam.ac.uk
CONTACT:Mustapha Amrani
DESCRIPTION:The exchange of meteorites among the terrestrial planets of ou
 r Solar System is a well established phenomenon. Similarly\, could solid m
 aterial be transferred between planetary systems? We examine a dynamical p
 rocess that yields very low escape velocities using nearly parabolic traje
 ctories\, and the reverse process that allows for low velocity capture. Th
 ese processes are chaotic and provide a mechanism for minimal energy trans
 fer that yield an increased transfer probability compared to that of previ
 ously studied mechanisms that have invoked hyperbolic trajectories. Howeve
 r\, they require a small relative velocities and would therefore be applic
 able when the stars are still embedded in their maternal cluster. We estim
 ate the transfer probability in a stellar cluster as a function of stellar
  mass and cluster size. We find that significant amounts of solid material
  could potentially have been transferred from the early Solar System to ou
 r nearest neighbor stars in the cluster. \n\nRegarding the exchange of km-
 size debris today\, given the high relative velocities between the Sun and
  its neighbors\, any incoming extra-solar debris would be identified as a 
 hyperbolic comet. No hyperbolic comet has been observed so far\, but futur
 e surveys with Pan-STARRS and LSST will provide wide coverage maps of the 
 sky to a very high sensitivity ideal to detect moving objects. In anticipa
 tion of these observations\, we estimate the number of extrasolar comets t
 hat might be detected taking into account recent results on the frequency 
 of planetesimal and planet formation (from debris disks and planet surveys
 )\, the amount of solid material that might be available to form planetesi
 mals (from protoplanetary disks studies)\, and the size distribution of pl
 anetesimals (from the study of the small body population in the Solar Syst
 em). 
LOCATION:Seminar Room 1 Newton Institute
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