Human migration and settlement of comets via genetically engineered trees.

This blog posting is a recycling of ideas in an essay by Freeman Dyson published as Chapter 24 in Scientist as Rebel. I feel the bullet point style in this blog posting promotes Dyson's ideas to a wider audience.

• Except for Earth, planets are not important for human habitation. Mars is waterless, and the rest are inhospitable for humans.

• Comets are rich in water, carbon and nirogen -the essentials to support life.

• Approximately one comet per year has a perturbation of its orbit such that it is captured into a region near enough to the Sun where it eventually evaporates and disintergrates. If one comet per year has been falling towards the Sun throughout the existence of the solar system, then the population of comets loosely surrounding the Sun likely numbers in the billions.

• Billions of comets, a few miles in diameter, would amount to habitable space ten to one hundred times the size of Earth.

• Comets are a plentiful platform for long-term space colonialization.

• Two essentials comets lack -air and warmth- could be added to the comet environment with introduction of biologically engineered trees.

  Components and Features of a Space Tree

  1. Leaf Skin

     Requirements of leaf skin designed for space:
     • Opaque to far-ultraviolet radiation in order to protect vital tissues from radiation damage.
     • Impervious to water.
     • Transmit visible light to the organs of photosynthesis.
     • Extremely low emission of far-infrared radiation, to limit the loss of heat and keep itself from freezing.
     • For the colder environment beyond Saturn additional features are needed for warmth: a compound leave that has photosynthesis and warmth in one part, and a cold mirror component that focused sunlight on the photosynthesis area. The mirror component could have genetic instructions to orient correctly towards sunlight.

  2. Branches -must be insulated to retain heat, a less complex challenge than insulating the leaves.

  3. Roots -will penetrate the comet, transferring heat to the roots system to melt ice into water (to service humans and the tree), and carry building block substances to the rest of the tree.

  4. Trunk -the trunk area would provide oxygen for humans, with the tree leaves genetically instructed not to release oxygen, but to carry the oxygen to the trunk area where it is released for human use.

  5. Size -ordinary wood has the ability to support its own weight, which if combined with the weak gravity of a comet ten miles or less in diameter should produce trees hundreds of kilometers in height. This size feature will greatly increase the ice melting and oxygen output for human use.