Dynamical and Biological Panspermia Constraints Within Multiplanet Exosystems

As discoveries of multiple planets in the habitable zone of their parent star mount, developing analytical techniques to quantify extrasolar intra-system panspermia will become increasingly important. Here, we provide user-friendly prescriptions that describe the asteroid impact characteristics which would be necessary to transport life both inwards and outwards within these systems within a single framework. Our focus is on projectile generation and delivery, and our expressions are algebraic, eliminating the need for the solution of differential equations. We derive a probability distribution function for life-bearing debris to reach a planetary orbit and describe the survival of microorganisms during planetary ejection, their journey through interplanetary space, and atmospheric entry.

This work is based on the published Astrobiology journal article:

Veras et al. (2018, Astrobiology, Volume 18, Issue 9, pp.1106-1122)

For example, this figure illustrates how the kick direction from the panspermia-generated collision affects the inclination of the ejecta orbit.

This figure illustrates the probability of life-bearing ejecta intersecting the orbits of the planets in the TRAPPIST-1 system: