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Exporting terrestrial life out of the Solar System with gravitational slingshots of Earthgrazing bodies

  • Amir Siraj (a1) and Abraham Loeb (a1)


Exporting terrestrial life out of the Solar System requires a process that both embeds microbes in boulders and ejects those boulders out of the Solar System. We explore the possibility that Earthgrazing long-period comets (LPCs) and interstellar objects (ISOs) could export life from Earth by collecting microbes from the atmosphere and receiving a gravitational slingshot effect from the Earth. We estimate the total number of exportation events over the lifetime of the Earth to be ~1–10 for LPCs and ~1–50 for ISOs. If life existed above an altitude of 100 km, then the number is dramatically increased up to ~105 exportation events over Earth's lifetime.


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Author for correspondence: Amir Siraj, E-mail:


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Exporting terrestrial life out of the Solar System with gravitational slingshots of Earthgrazing bodies

  • Amir Siraj (a1) and Abraham Loeb (a1)


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