Enhanced interplanetary panspermia in the TRAPPIST-1 system

Understand

We present a simple model for estimating the probability of interplanetary panspermia in the recently discovered system of seven planets orbiting the ultracool dwarf star TRAPPIST-1, and find that panspermia is potentially orders of magnitude more likely to occur in the TRAPPIST-1 system compared to the Earth-to-Mars case.

• As a consequence, we argue that the probability of abiogenesis is enhanced on the TRAPPIST-1 planets compared to the Solar system.
• By adopting models from theoretical ecology, we show that the number of species transferred and the number of life-bearing planets is also likely to be higher, because of the increased rates of immigration.
• We propose observational metrics for evaluating whether life was initiated by panspermia on multiple planets in the TRAPPIST-1 system.