Planet 9 - probably not a scooped up exoplanet: suggestions that Planet 9 formed outside our solar system, or was even stolen from a rival system, have been dealt a blow by investigations into the likelihood of planetary capture by young stars

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Planet 9 - probably not a scooped up exoplanet: suggestions that Planet 9 formed outside our solar system, or was even stolen from a rival system, have been dealt a blow by investigations into the likelihood of planetary capture by young stars