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Contrary to previous models of solar system formation, new simulations by Levison et al. suggest that some long-period comets in the Oort cloud did not form in our Sun’s protoplanetary disk, but were captured from the protoplanetary disks of other nearby stars when the sun was in its "birth cluster." The calculations account for why the Oort cloud is more populous than predicted, and suggest that as many as 90% of Oort cloud comets originated from other stars. The movies shown here depict two mechanisms for capture: random capture of comets (first movie clip), and direct transfer of comets from the scattered disk of one star to the Oort cloud of another (second movie clip).