Like a modern-day Johnny Appleseed, Michael Mautner proposes sowing the seeds of life not merely here on Earth, as did the arboreal propagator of legend, but throughout the cosmos.

Mautner, a senior research fellow at Lincoln University in Canterbury, New Zealand, advocates sending packets of freeze-dried microbial life cruising on solar sails through space, spreading the DNA of terrestrial life beyond Earth in an act of what he calls "ultimate altruism."

After a journey of more than 5 million years, the packets would theoretically arrive at distant planets, take root, flourish and introduce life there as may have happened here on Earth so many billions of years ago.

The proposal, which he claims could be feasible by 2050, flips on its head the theory of Panspermia, which suggests microorganisms from other planets seeded life here on Earth, arriving piggyback on meteorites, comets, asteroids or tiny particles of dust.

"Our first responsibility as living beings is to secure the future of our type of organic life," Mautner wrote in an e-mail correspondence with SPACE.com.

"The more one studies biology on all levels, the more unique and wonderful life is revealed to be," Mautner continued. "However, life will come to an end in this solar system. For a long time, we cannot be sure if it exists elsewhere. We also cannot be sure how long our technological civilization will last. We have the ability now to secure life in the universe, and we should make sure to fulfill this most basic duty."

"I dont think putting spores in a baggie and shooting them off is a beneficial thing."

The proposal would rely on sending a swarm of microbial packets each containing as little as one-tenth of an ounce (several grams) of freeze-dried algae or other organisms riding outward in a flotilla of solar sails. The technology, now under development, relies on the gentle but steady pressure of light to propel the sails through space.

The sails could target young planets to seed, perhaps with the help of robotic navigational aides. The probes could also alight on meteorites or carbonaceous asteroids, where readily available nutrients could foster the microbial life as an intermediate step until slamming into a young planet at a future date.

Predictably, Mautners proposal doesnt make him much of a hero among those who seek to protect other planets from terrestrial life.

In fact, Article IX of the 1967 Outer Space Treaty seems to expressly forbid such an undertaking.

The treaty, which governs the exploration and use of outer space, reads in part, "States Parties to the Treaty shall pursue studies of outer space, including the moon and other celestial bodies, and conduct exploration of them so as to avoid their harmful contamination."

"The key word there is harmful," said John Rummel, NASAs planetary protection officer. "I dont think putting spores in a baggie and shooting them off is a beneficial thing. Its not a responsible thing to advocate."

Indeed, NASA and other space agencies now go to incredible lengths to ensure any and all interplanetary spacecraft are as free from spores and other forms of life before launch. The twin Viking landers, for instance, were practically oven-baked before they were launched to Mars in 1975.

But Mautner, the driving force between a tiny internet discussion group called The Interstellar Panspermia Society, said the effort would focus on star-forming clouds where life would not have had time to evolve, based on the terrestrial analogue.

One such target would be the star-forming cloud Rho Ophiuchus, which lies 520 light-years from Earth. Any journey there could take as long as 5.2 million years.

Freeman Dyson, a physicist at the Institute for Advanced Study in Princeton, New Jersey, and a proponent of human colonization of the solar system and beyond, said he has no qualms about the idea.

"I find the tendency of life to spread around and colonize all unoccupied space very attractive," Dyson said.

"If we actually discovered some spores coming in from space and producing completely different life forms, wed be thrilled. Its not something I would be frightened by at all. It would be enormously exciting to observe a second kind of life, and aliens might feel the same way when they receive our seeds."

Rummel called the idea foolhardy.

"You might feel like you made your mark on the universe, great, but there might be more productive things to do with your time," Rummel said.

Mautner argues that the effort would at most seed only a few thousand worlds with life.

"And even if we succeed to enliven our whole galaxy, this will still leave another hundred billion untouched," Mautner said.