Exoplanetscape 7

More of my planetary speculations can be seen in my DA "Paleo & Sci Illo" gallery:

[link]

This is the first planet with a well-developed biological system that I have depicted in this series. It is an earth-like world of .65 Earth masses. it is larger in diameter than Mars.

This world orbits an M class red dwarf smack in the middle of its "Goldilocks Zone" where liquid water can exist at the surface. Unfortunately its position closer to its sun than Mercury is to our sun dictates that the planet is in tidal lock. One face of the orb always faces its parent star. The "noon point" where the sun is directly overhead is so hot that water boils away. This creates a permanent global Hadley cell convection of the atmosphere. A high pressure dome exists over the sunlight side that rises and transfers heat at high altitude to the night side. At the antipod on the perpetually dark side the hot air cools and sinks. A hemispheric "Ice Age" exists on the night side. Low altitude winds recycle cooled air back to the daylight side.

The habitable zone of the planet contains not a biosphere but rather, a "bioannulus". It is a narrow ring perhaps a hundred km wide that wraps completely around the planet along its terminator. It is perpetual sunrise facing the sun. Turn your back to the sun and it is perpetual sunset.

Evolution within this life ring is driven by competition for the best longitudes for light exposure. Good realestate comes at a premium. For billions of years, plant life has been in a race to reach the best light. The result that you see here are towering growths that girdle the planet like living skyscrapers in Midtown Manhattan.

The emmergent bulb topped "trees" are all taller than the Empire State Building. Hydrogen is separated from water to give these balloon envelopes bouyancy. They resemble barrage balloons during the London Blitz. They are covered in symbiotic plants that share the view and anchor the gas bags to the ground below. If a bag breaks loose, it rises sunward until it is caught by the high altitude wind and reverses course. In the hot wind it bursts and sheds seeds and clonal capsules back into the habitable zone.
The air bags are eqipped with compound parabolic lenses that focus light. Each envelope is the size of an airship.

The canopy is divided into many levels delineated by both light level and barometric pressure. This mature "forest" where individual plants may live for thousands of Earth years is very stable and hosts a complete array of animal life.

Bioannuli may be more common in the universe than biospheres.

art & text (c) John P. Alexander