Transfer of Life-Bearing Meteorites from Earth to Other Planets

TL;DR

This paper investigates the likelihood and mechanisms of Earth-originating meteorites, potentially carrying life, being transferred to other planets within and outside our Solar System, suggesting possible interstellar seeding of life.

Contribution

It provides a quantitative analysis of Earth meteorite transfer probabilities to other planets and interstellar space, considering biological viability during interstellar journeys.

Findings

Earth meteorites can reach exoplanets over 20 light-years away.

Fragmented ejecta may seed comets and icy bodies with fertile material.

Micro-organisms could survive interstellar transfer and propagate through the Galaxy.

Abstract

The probability is investigated that the meteorites originating on Earth are transferred to other planets in our Solar System and to extra solar planets. We take the collisional Chicxulub crater event, and material that was ejected as an example of Earth-origin meteors. If we assume the appropriate size of the meteorites as 1cm in diameter, the number of meteorites to reach the exoplanet system (further than 20 ly) would be much greater than one. We have followed the ejection and capture rates estimated by Melosh (2003) and the discussion by Wallis and Wickramasinghe (2004). If we consider the possibility that the fragmented ejecta (smaller than 1cm) are accreted to comets and other icy bodies, then buried fertile material could make the interstellar journey throughout Galaxy. If life forms inside remain viable, this would be evidence of life from Earth seeding other planets. We also estimate the transfer velocity of the micro-organisms in the interstellar space. In some assumptions, it could be estimated that, if life has originated $10^{10}$\ years ago anywhere in our Galaxy as theorized by Joseph and Schild (2010a, b), it will have since propagated throughout our Galaxy and could have arrived on Earth by 4.6 billion years ago. Organisms disperse.