This week I had two new papers formally published.
The first of these, A Field Guide to Finding Fossils on Mars, was written with a host of co-authors from the NASA Astrobiology Institute. This paper aims to help forthcoming NASA and European missions to search for traces of ancient life on the red planet. Three or four billion years ago, Mars was warm enough to sustain lakes, rivers, and maybe oceans. These water bodies produced sediments rich in iron, silica, and clay — components strongly favourable to the formation of fossils, for reasons that are well understood and experimentally verifiable. On Earth, rocks this old have been scrambled, destroyed and recycled by the movements of tectonic plates and by the erosive action of liquid water. But on Mars, a much drier and less dynamic planet, rocks of this age are well preserved and easy to find in crater-lake and river deposits. Right now, we argue, these rocks are the best place to look for fossils on Mars — better than the other candidates, which include possible hot-spring silica “sinter” in Gusev Crater, rare carbonate minerals, salt deposits, and mineral-filled pores in volcanic rocks (these might be explored one day, but need more work to resolve critical uncertainties and objections).
The second paper, Exogeoconservation: Protecting Geological Heritage on Celestial Bodies, was a joint effort led by Jack Matthews of Memorial University, Newfoundland and the Oxford University Museum of Natural History. This paper contributes to an ongoing scholarly discussion about how to avoid messing up other planets in the same ways we’ve messed up the Earth (or in whole new ways). Jack is a keen proponent and practitioner of “geoconservation”, a long-established practice and body of knowledge concerned with conserving geological features that are especially valuable for scientific, aesthetic, cultural, historical or ecological reasons. Geoconservation takes care of places that are special to us even though they may be devoid of life; an activity different from, but complementary to, biological conservation. Rather than “re-inventing the wheel”, we suggest that those who want to avoid the destruction of barren rocky and icy places in our solar system look to the hard-won successes of geoconservation for theoretical and practical lessons. In particular, legal arguments favour a new treaty to regulate geoconservation in outer space (which we call “exogeoconservation”) along similar lines to the Antarctic Treaty on Earth.