Whispering Abyss
A Lovecraftian horror habitat under immeasurable pressure
Orbiting a gas giant with 0.8 times the mass of Jupiter, this Mars-sized exomoon is a fascinating world. Its composition is rich in volatiles, making it less dense than Earth, with a surface dominated by an immense ice crust, stretching 900 kilometers deep, with three different layers. The exterior, formed due to the extreme cold from being far from its star, creates a frozen shell. Beneath this lies a vast ocean, insulated from the frigid vacuum of space. This ocean is so deep that the immense pressure from the overlying ice and the moon’s gravity compresses the water below, forming an interior crust of exotic, high-pressure ice. The inner ice layer typically isolates the ocean from the rocky crust, but the exomoon’s eccentric orbit around the gas giant generates enough internal heat to drive massive volcanic activity. These volcanoes penetrate the internal ice crust, allowing huge basaltic flows and hydrothermal fields to emerge. These dynamic geological processes bring essential minerals to the surface, creating rich, mineral-laden oases.
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
|
|---|---|---|---|---|
|
Exomoon
|
0,12 (Me)
|
0,55 (Re)
|
4,04 (g/cm3)
|
0,40 (g)
|
|
Type
|
Mass
|
Radious
|
Light
|
Temp.
|
Year
|
|---|---|---|---|---|---|
|
M
|
0,465 (Ms)
|
0,464 (Rs)
|
2,88% (Ls)
|
4771 (K)
|
1934,5 (days)
|
Surface and Atmosphere
The exomoon’s thin atmosphere, though sparse, supports wind, snow, and electrical activity. Temperatures are frigid, allowing CO2, methane, and nitrogen to freeze, forming glaciers on the surface. The gas giant’s powerful electromagnetic field often generates spectacular auroras, painting the sky with vibrant colors.
Additionally, the thin atmosphere contains diamond dust, creating enormous, shimmering halos that encircle the moon. These unique atmospheric and geological features make the exomoon a captivating and dynamic world, with its icy landscapes and dazzling light displays offering a stark contrast to the dark, cold expanse of space.
Basaltic flows oasis
Beneath the deep ocean, exotic ice formed under immense pressure is melted by hot plumes from the mantle. Magma floods expand over the area, and dark columns of water mixed with volcanic gasses, ash, and minerals rise high. The magma eventually cools, creating a basaltic plain. The water from the plumes is rich in minerals, which precipitate to the bottom, enriching the plains.
Here, orange extremophile bacteria, resistant to extreme heat, thrive by feeding on minerals, hydrogen, and sulfur. These bacteria form the base of a unique ecosystem, where crab-like creatures feed on them, adapting to the harsh environment. The views in these depths are amazing, with orange light from the hot magma illuminating layers of basalt, orange bacteria, and dark crabs.
Hydrothermal fields
When the basalt plains cool, the main volcanic activity stops but is still hot underneath. The melted exotic ice creates a fluid hypersaturated with minerals.
When superheated, this fluid forms fields of hydrothermal vents, while cooler conditions result in a brine-like liquid, denser than water, which can create pools and rivers on the ocean floor. A thick layer of chemosynthetic bacteria thrives here, feeding on methane from decaying organisms, sulfur, and hydrogen from hydrothermal vents, and minerals from the brine.
These bacteria form the foundation of a unique ecosystem. Bioluminescent jellyfish-like organisms, glowing in the dark waters, move through the water column, absorbing various minerals. Colonies of red and black mussels also thrive here, living in clusters around the hydrothermal vents nad small brine pools.
This vibrant ecosystem showcases the incredible adaptability of life in extreme conditions, with its glowing inhabitants and the interplay of heat, minerals, and life.
Whispering Abyss could be an exomoon around the gas giant exoplanet GJ 849 b, in a distant orbit at the red dwarf star Gliese 849. Is located 29 light-years away in the constellation Aquarius. The planet has a minimum mass of 0.82 times that of Jupiter, takes approximately 5.16 years to complete one orbit and was discovered in 2006 by the radial velocity technique.
More information about GJ 849 b: