Planetary Geoarchaeology of Comets: Site Formation Processes on 67P/Churyumov–Gerasimenko

Abstract

On November 12, 2014, 10 years after its launch as part of the European Space Agency's (ESA) Rosetta Mission, the Philae lander successfully touched down on the surface of 67P/Churyumov-Gerasimenko (hereafter 67P/CG). This event was significant for two reasons. First, it was and remains the only successful attempt to orbit and eventually land on a comet's surface, opening up myriad possibilities for the scientific study of surface processes on this type of celestial body. Second, the landing of Philae, coupled with the eventual crash of the Rosetta spacecraft, officially initiated the formation of an archaeological record on 67P/CG. Here, we provide a review of comet surface and archaeological site formation processes and introduce the Rosetta mission as a case study for the application of planetary geoarchaeology. Our results suggest that although dynamic, the cometary environment is capable of preserving archaeological material within narrow windows of time. Specifically, this “preservation window” is dependent on several key geological factors, including local sublimation activity, fracturing, mass-wasting events, outbursts, large-scale splitting of parts of the nucleus, sedimentary processes, pit formation, meteoritic impacts, and rotational instability. As we continue to expand our material footprint across the solar system, we believe planetary geoarchaeology will offer crucial insights into the preservation of space heritage and the growing archaeological record of space exploration.