Our 5-million-year mission: to send life to strange new worlds
IF LIFE on Earth is a wondrous thing, then how much more wondrous would life be on 100 Earth-like worlds? This is more than idle speculation. We may have the power to turn that fecund dream into reality.
Michael Mautner of Virginia Commonwealth University in Richmond advocates sending interstellar seed-pods out to promising star systems to disperse bacteria and other microbes. The hope is that they will find fertile ground, multiply and diversify into new life forms (see 鈥淭o boldly sow: Seeding the galaxy with Earthly life鈥�). If humans cannot cross the vast distances to other stars in person, then this might be the only way to spread terrestrial life beyond our solar system.
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The idea is not without its detractors. Some say it would be an arrogant and reckless act: if life is already established on an alien world then our emissaries might infect the natives or guzzle their food, maybe even wipe out the biosphere.
Arguably that is a slender risk, which can be further reduced by choosing newborn star systems where there has been too little time for life to originate. But perhaps it would still be wise to wait a few decades until we have a census of exoplanet atmospheres to show us how common life might be in our galactic neighbourhood.
A more subtle question is why we should bother. These missions may take millions of years to bear fruit, so human civilisation would probably never know the result. Whether you think it is worth it comes down to personal taste and your reproductive inclinations. To those of a nurturing tendency it may well seem pointless, even perverse, to put in the effort without being able to watch over your progeny, and without even the prospect of seeing some photos of the grandchildren. It would hardly be akin to raising a family. It would be a more cool, speculative affair, like a trip to the sperm bank.
Neither are we talking about our own direct offspring. Still, we owe our own existence to the struggles of countless microscopic life forms in Earth鈥檚 early history, and perhaps now we have the opportunity to start the process all over again.
There may also be a less altruistic motive for firing microbes at the planets around distant stars 鈥� a genuine reproductive imperative. Even bacteria and algae share some genes with humans, genes that could find countless new opportunities in the galaxy. A twinkling flotilla of spacecraft cast into the darkness might be the ultimate expression of the selfish gene.
Finally, it should be pointed out that we are not necessarily the first creatures to have thought of this. Our Betelgeusian forefathers may have had the same idea 4 billion years ago, and sent their seeds to fall on the fresh Earth. In that case, let鈥檚 carry on the tradition and maintain the galactic chain of life.
While the task would be much easier than hurling people across the void, such a scheme will still cost millions of dollars. So it seems unlikely that any corporation or space agency could justify the expense to their shareholders or governments. Perhaps what is needed is a rich individual to put up the cash. What would be the greatest legacy: a new library, an art gallery, a hospital wing, or a billion new species of life? Philanthropic panspermia might just be the ultimate charitable donation.