Searching for Jupiter and Saturn analog planets with potential icy exomoons -- a Panspermia perspective

TL;DR

This study explores the potential for icy exomoons around Jupiter and Saturn-like exoplanets to support life and facilitate panspermia, analyzing candidate systems and their implications for microbial transfer to Earth.

Contribution

It identifies specific exoplanetary systems with icy satellites that could have hosted life and assessed their potential role in panspermia based on system age and impact dynamics.

Findings

Eleven exosystems with candidate icy satellites were identified.

Older systems may have had higher ejection chances due to asteroid impacts.

Younger systems could be better sources for microbial transfer.

Abstract

Considering the possibility of complex organic molecules and microbial life appearing under the ice shell of those satellites in the Solar system, this study investigates the possible analog sources (targeting the potential ice satellite hosting, Jupiter and Saturn-like planets in exoplanet databases) and the transport of such bioaerosols in an attempt to support or contradict Panspermia, a fringe theory about the fertilization of Earth. Along many general parameters of the candidate planets, the host star, and the star system, additional factors thought to be related to Panspermia were also considered (e.g., the evolution of icy satellites, the frequency of impact related ejection, the traveling time from a source, and so on), revealing the following results. Eleven exosystems, with candidate gas giants hosting icy satellites, were found in a database listing more than 5000 exoplanets. The exomoons of the oldest systems (c.a. > 8 Ga; HD 191939, HD 4203, and HD 34445) could have developed rapidly considering the short formation time (~100 Myrs), which may result in the overlap of the putative early biological evolution and asteroid bombardment phase, providing a higher chance to bioaerosol ejection to space due to frequent collisions. However, the direct transfer might have occurred too early, even before our Solar system was formed, which prevented the fertilization of the latter. A longer formation of the exomoons (~3 Gyrs) significantly reduces the chance of ejection into space by asteroid impacts, which become less frequent over time, but increased the chance of arrival in time to the Solar system. Younger systems, such as HD 217107, HD 219828, HD 140901, and HD 156279 (c.a. 4 to 6 Ga), are better candidates of putative microbe source if the short icy satellite formation, along the higher impact and ejection frequency are expected considering direct transport from those systems.