Panspermia, Octopuses, and Comets 2/6

Comets as vectors of life

Credit: ESA — The analyzes carried out on data collected by the Rosetta spacecraft made it possible to establish that the jets emitted by Comet 67P/Churyumov — Gerasimenko contain, among other compounds, organic molecules and molecular oxygen

Comets hosting possible microbial life

As we have seen in the first part of this story, the study’s authors believe it is extremely unlikely that complex biological structures such as enzymes could have formed by chance, especially in an environment subjected to hellish conditions, such as those existing on Earth during the Hadean.

But the hypothesis that life was brought to Earth from space would not be scientifically sustainable if it were based solely on statistical considerations such as those discussed so far.

Well aware of this, panspermia’s advocates accumulated a set of evidence, or rather clues, supporting the hypothesis of the extraterrestrial origin of life. To be sure, each of the pieces of evidence they propose is at least questionable. However, taken all together, they form a coherent picture, which makes panspermia — according to its supporters — far preferable to abiogenesis as an explanation of the origin of life.

The first clue to support their conjecture concerns comets, which in the panspermia model have a central role. If indeed these ancient bodies were the vectors of life, it is necessary to demonstrate that they contain, or may contain, biological material.