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Essays - Theories and Opinions

The Value of Martian Microbes

By Mark Lupisella
February 1, 2005

"If there is life on Mars, I believe we should do nothing with Mars. Mars then belongs to the Martians, even if they are only microbes."
       — Carl Sagan, Cosmos

On earth, we go out of our way to kill microbes. On Mars, we will go out of our way not to. For scientists working in NASA's astrobiology program, the reason is obvious. We want to know more about how life emerged and what the possibilities for life are. We want to know where life has been, and if we're lucky, maybe something about where it's going.

All life on earth is thought to have evolved from one common ancestor, and so in that sense, we know only one kind of life. Some might say we only have one data point, and so we can only begin to imagine what life might be like "out there." For that reason, we must be extremely careful not to modify, mask or destroy what we're attempting to find — NASA's own version of a Heisenberg uncertainty principle for biology, or for Star Trek fans, an example of the "prime directive" applied to very primitive life.

NASA and other space agencies have a long history of trying to protect extraterrestrial life by adhering to policies requiring clean spacecraft. But a human mission to Mars will present unusual contamination concerns. Preserving the integrity of indigenous Martian life may prove to be tremendously challenging, burdensome and costly, and so the effort we put into protecting Martian life will be a matter of how much we care and why. We will certainly care for scientific reasons, but how far are we willing to go? And what about the non-scientific value of possible Martian microbes?

Complicating matters further is the idea of "ecosystem synthesis," the intentional creation of large-scale ecosystems on other planets. Some would like to "terraform" Mars, which means heating up and "watering" the planet to create an Earth-like atmosphere. Whether this is even possible is an open question, but it raises the distinct possibility that ecosystem synthesis endeavors such as terraforming could have serious negative effects on any life that might be found on Mars, including extinction. Others have suggested creating an ecosystem on Mars that would allow indigenous life to flourish.

The scientific and wider communities are attempting to address these questions. Recently, the American Association for the Advancement of Science Dialogue on Science, Ethics, and Religion concluded a series of interdisciplinary workshops to address some of the broader issues. These meetings revealed a wide range of views on how Martian microbes might be valued, ranging from more traditional "rational-centric" ethical views, in which only rational creatures are worth protecting, to "cosmocentric" views, which treat value in broader cosmic terms.

This dialogue will continue to be necessary to the search for extraterrestrial life. Finding an independent origin of life (as opposed to life that is related to Earth life) could have significant relevance for broader ethical and scientific questions. An independent origin of life might be valuable for reasons that our Earth-bound ethical perspectives aren't equipped to handle. For example, the uniqueness of a different kind of life might be valued because it contributes to cosmic diversity in a compelling way.

Might this afford Martian microbes a level of value we're not used to ascribing to such primitive life forms? Might it afford Martian microbes "rights" as suggested by Carl Sagan's admonition? Regardless of one's intellectual rationalizing, it does seem intuitively reasonable that extraterrestrial life, no matter how primitive, should be valued differently from Earth microbes.

A "cosmically local" independent origin of life (e.g. in our solar system or galaxy) could suggest that life emerges naturally, and that life likely exists throughout the universe. This would support much of today's speculation and theory. Would this make us more at home in the universe, perhaps less inclined to seek a creator? Or would the ubiquity of life throughout the universe simply reflect the greater glory of God, as some in the theological community suggest?

Given the potential relevance for all of humanity, it would seem appropriate to pursue robust international consultation and involvement on the broader implications of the search for extraterrestrial life. This is especially true of a human mission to Mars which could be the beginning of terraforming, as well as any other ecosystem synthesis that humanity attempts on another world.

The prospect of extraterrestrial life offers a new kind of lens through which to see and re-evaluate some of our most basic questions. We are stirred to consider broader ethical perspectives and worldviews. We are prompted to explore how extraterrestrial life might affect not only how we see life and ourselves in the universe, but how we might act in the universe as well. Such prospects are well worth preserving.

Mark Lupisella Mark Lupisella is an engineer and scientist at the NASA Goddard Space Flight Center where he worked for many years on the Hubble Space Telescope. He now works in advanced concepts and astrobiology.