Ethereal Waves
A thriving ocean under a cold and dim red dwarf star
An ocean world that orbits inside the habitable zone around an ultra-cool red dwarf with just 9% of the mass of our Sun. The planet is a super earth, with a high level of geological activity sustained partially on the decay of radioactive elements on its core, and partially on the tidal effects of neighboring planets. Like most of the worlds around red dwarfs, the habitable zone is close to the star, the planet completes an orbit in just 12 days, and is in a tidally locked state where one side always faces the star and the other is in perpetual night. A combination of deep oceans of 60 km and an atmosphere rich in CO2 are able to transport enough heat around the planet preventing the night side from being frozen, whilst cooling the dayside to an average temperature of 18 degrees.
Planet summary
The following table summarizes the characteristics of this planet, comparing its mass, radius, and gravity with that of the Earth (Me, Re and g). A similar table can be found below, comparing the characteristics of the star’s mass, radius, and light with our Sun (Ms, Rs and Ls).
|
Type
|
Mass
|
Radious
|
Density
|
Gravity
|
|---|---|---|---|---|
|
Superearth
|
1,34 (Me)
|
1,13 (Re)
|
5,10 (g/cm3)
|
1,05 (g)
|
|
Type
|
Mass
|
Radious
|
Light
|
Temp.
|
Year
|
|---|---|---|---|---|---|
|
M
|
0,09 (Ms)
|
0.119 (Rs)
|
0,06% (Ls)
|
2566(K)
|
12,4(days)
|
Atmosphere and surface features
The star itself is much cooler and dimmer than our Sun, emitting most of its energy in the infrared region, and very little of visible light, just 0.05% when compared with our Sun. This means that even if the planet is warm because it receives a total amount of energy comparable to our planet Earth, experiences a much dimmer skies comparable to a full moon on our planet.
Even on the day side under clear skies, everything feels dark. But this can change suddenly when huge flares rise from the star, temporarily increasing its brightness. Usually this flares are dangerous, but thanks to its internal heat Ethereal waves create powerful magnetic fields that shield the atmosphere from the worst effects.
The column of warm water rises dozens to hundreds of meters, until it is cold enough to stop and spread horizontally. This process can create layers where different gasses and minerals are more abundant.
The ocean
A warm global ocean means a lot of water vapor to drive huge storm systems around the planet, and several giant hurricanes can be active simultaneously. The high electrical activity, and the burst of UV radiation from the stellar flares support an active chemical on the atmosphere, creating complex compounds that dissolves on the surface of the ocean.
The bottom layer of the ocean is warmed by the head conducted through the crust, and thanks to the high pressure is saturated with minerals and gasses coming from magma, volcanic eruptions and hydrothermal vents.
This layer is unstable, and tends to rise in huge plumes of warm water, initially driven by the convection, but later also by the decompression which releases bubbles of gas. When these plumes arrive at the surface, warm water rich in minerals and gasses is mixed with cold surface water rich in organic compounds.
Life on the ballon seas
An ecosystem driven by bacteria that feed from hydrogen sulfur, and fixed nitrogen from the atmosphere lives at the top layer. Some of these bacteria create symbolic communities, forming balloons full of gas that varies from microscopic to several centimeters. They try to be as close as possible to the surface, where more organics and nitrogen are available, but regulate the deep to avoid storms and lethal bursts of UV radiation from solar flares. Some of these balloon creatures are bigger and more complex, with huge filamentous roots that sink hundreds of meters into more mineral rich waters.
The floating reefs
The most complex communities are the floating reefs, huge structures located dozens to hundred of meters below the surface. The core is formed by balloon creatures in association with bacteria able to fix minerals from the water, creating solid structures that protects the community from predation. The balloons full of gas provide buoyancy to keep the reef to an optimal deep. The floating reef survives from extracting minerals and sulfur with deep roots, and feeding on the organic matter falling from dead organisms from the surface.
A world like this could be around the ultra-cool dwarf star TRAPPIST-1, with seven confirmed Earth-sized rocky exoplanets, some of them in the habitable zone, like TRAPPIST-1 g. The star system is located 40 light-years away in the constellation Aquarius, and was in 2016 by the transit method. This scenario mirrors the early history of Earth, long before photosynthetic life developed, and when it was restricted to the oceans, and could also represent the far future of the gas giants of the solar system, when the sun melted the icy moons in his way to become a red giant.
More information about TRAPPIST-1: