Panspermia, the idea that life might travel through space to seed other planets and even other star systems, is a fascinating topic for conjecture, and our understanding of the survival of various forms of life in extreme environments only adds to its appeal. But just as SETI has an active counterpart that seeks to send rather than simply receive interstellar messages, so panspermia has its own advocates for a new kind of mission: To seed the stars from Earth. A group called SOLIS (Society for Life in Space) has sprung up around the notion. Its goal:
To propagate our family of organic Life throughout the Milky Way Galaxy and beyond. We propose to seed young planetary systems in star-forming interstellar clouds. We shall design and launch directed panspermia missions carrying the microbial representatives of Life by the year 2050.
So says the SOLIS Web site and so says society coordinator Michael Mautner, who is a research professor in chemistry at Virginia Commonwealth University. Mautner has in the past worked with solar sail expert Gregory Matloff on propulsion systems that would make it possible to seed new solar systems and has written up the idea for the Journal of the British Interplanetary Society. Now he offers a new paper for the Journal of Cosmology that focuses on what he believes to be our obligation to proceed with directed panspermia, ensuring that life does not come to an end.
Panspermia as Obligation
In a short article at Physorg.com, Mautner states his premise:
“We have a moral obligation to plan for the propagation of life, and even the transfer of human life to other solar systems which can be transformed via microbial activity, thereby preparing these worlds to develop and sustain complex life. Securing that future for life can give our human existence a cosmic purpose.”
The idea is that once we have identified planets with conditions suitable for life (and protoplanetary situations where life might one day develop), we should send organisms to seed these worlds as a way of accelerating local processes of evolution. Even the arrival of such a payload onto a comet or asteroid in a distant planetary system could pave the way for its eventual transportation to a habitable planet by local panspermia, in much the same way that material from Mars has occasionally made its way to Earth.
From accretion disks and interstellar clouds to planets identified by Kepler as being in the habitable zone of their stars, the list of targets should be extensive. The propulsion challenge is less of a problem than you might think, for Mautner is in no hurry to get there. Solar sail methods might take hundreds of thousands or even millions of years to deliver their payload, but the idea is long-term survival of life. Capsules containing about 100,000 microorganisms each and weighing 0.1 micrograms would be the delivery mechanism.
Ethics Among the Stars
All of which leads us to the ethical dilemma. How do we choose our targets so as not to disturb already existing life? Mautner considers this in his paper (internal references omitted for brevity):
Can panspermia missions perturb existing extraterrestrial life? At present, there is no conclusive scientific evidence for extraterrestrial life; though admittedly not all scientists share this opinion… Every living cell needs thousands of complex components as DNA, proteins and membranes, and the probability of these components coming together to originate life may be very small even on billions of planets…
If we still detect extraterrestrial life, we can avoid these targets. In any case, we can target new solar systems where life could not have evolved yet. We may seed a few hundred new solar systems, that will secure the future of our family of gene/protein life but will leave all the other hundred billion stars in the galaxy and their possible indigenous life unperturbed.
Yes, we can target locations where life is not likely to have already evolved, but how accurate can our assessments be given the constraints of current observational technology? Moreover, even that approach leads to potential problems. Panspermia assumes movement of life’s building blocks and even life itself through space. Seed a planetary system with life and it could be millions of years before that life moved from an asteroid in the system to a planet in the habitable zone, one that in the interval had developed life forms of its own. We can never be sure we are not displacing local life.
Mautner thinks even this scenario is not a showstopper:
If there is local life there that is fundamentally different, it will not be affected; if it is gene/protein life, it may be enriched and we can induce higher evolution. The new biospheres may prepare the way for human colonization if interstellar human travel becomes possible.
Which Life Survives?
But I’m thinking that sending cyanobacteria to other star systems to consume toxins and pump out oxygen is a dangerous form of meddling because it assumes that forms of life related to our biosphere are the ones that should survive. Ian O’Neill has an amusing but pointed take on this in a recent post:
If our life takes hold of a planet where another life had the opportunity to evolve into an interstellar civilization in a couple of billions of years time, wouldn’t we be in violation of some kind of cosmic anti-monopoly regulation (or at least in violation of the Prime Directive)?
And there’s another thing to ponder: What if “life” is the universal equivalent of some kind of infection. Is life rare because the universe has a very strong immune system? Firing our genetic code far and wide could be considered to be biological pollution.
I’m all for spreading the human influence around the galaxy, but I think this can only be considered if we physically go to these alien worlds, to evaluate these places in person before we start setting up home. Blindly sending life from Earth to habitable worlds and planet-forming accretion disks seems a little reckless, especially as we have no clue about the consequences if we started impregnating unsuspecting planets.
As we await results from Kepler and more from CoRoT, we still have no realistic assessment of the number of terrestrial planets around stars in our galaxy, nor do we have spectroscopic data that can tell us whether or not such worlds bear life. Is the meaning of life wrapped up in self-propagation, as Mautner’s paper suggests? If so, then pushing life from our biosphere outward is simply fulfilling our basic purpose.
But perhaps there is more to life, including the ethical responsibility to let life take its own directions in those niches where it has already taken hold. I’m not persuaded by a panbiotic ethics that doesn’t take into account the huge gaps in our knowledge about how and where life may form.
The paper is Mautner, “Seeding the Universe with Life: Securing Our Cosmological Future,” Journal of Cosmology Vol 5, (January, 2010), pp. 982-994 (available online).