Thanatos IV is an exoplanet covered in dense, humid, and mountainous jungles. These jungles are primarily inhabited by amethyst-colored flora that is remarkably similar to what is found here on Earth. When compared to Earth, it is 1.3 times as massive, and is 1.2 times larger in radius. As such, its gravity is around 90% of what it is here on Earth. The planet is not at a tilt, meaning there are no seasonal changes year-round.
The native flora being the distinctive amethyst color is a result of Bacteriochlorophyll B taking the place of the chlorophyll found in plants on Earth. However, the natural processes these plants go through are remarkably similar otherwise. This results in the plants entirely absorbing the green light they take in, while rejecting some of the blue light and almost all of the red light. It likely adapted this way in order to reduce the amount of harmful solar radiation received from the star at the center of the system.
To their knowledge, humanity is the only sapient creature on the planet. This is certain to them. Hopefully. Nothing even comes close, both because of how the evolution of life on Thanatos was set back by the Solar Combination, and because there simply hasn’t been enough time for it to develop otherwise.
The ‘Solar Combination’ was an event that took place a few million years ago when a rogue Red Dwarf star entered the system and collided with the yellow star at the center of the system. Despite the typically violent nature of such an event, Thanatos IV survived mostly unscathed. The change in the star’s size and output resulted in a mass extinction which favored those which had adapted to favor the far warmer temperatures.
Due to neon gas making up about 2.1% of the atmosphere, there are frequent events where charged particles excite the atmosphere and create a beautiful blood-orange glow somewhat similar to the Aurora Borealis on Earth. However, when compared to the aforementioned Northern Lights, these events are significantly more frequent and span far more of the planet simply because of Neon’s sheer volume in the atmosphere.
The rest of the atmosphere is made up of 0.5% methane, 0.5% ozone, 1% argon, 1% carbon dioxide, 2% water vapor, 26.25% molecular oxygen, and 66.6% molecular nitrogen. The other .05% is accounted for by other trace gases. The atmosphere is significantly thicker than Earth’s, and estimates place it being at around 7.5 times the pressure of Earth’s atmosphere at sea level. This thick atmosphere evenly distributes temperatures across the entire planet so that they are consistently ideal for sustaining the dense jungles that cover the planet’s surface.
The tallest point on Thanatos IV is at the top of a large stratovolcano similar in scale to Olympus Mons on Mars. Its top nearly scrapes the top of the troposphere, being 1.873 km above sea level. At its very peak, the atmosphere’s pressure is still about what it is at sea level on Earth. Many of the highlands on the planet reach above 9000m, or about the same height as Mt. Everest, meaning they are habitable for the average human at about 3 atmospheres of pressure.
In comparison to the highlands, the lowlands and oceans are uninhabitable for average humans, meaning only those in pressurized suits or with heavy augmentations are able to visit them. This means that heavy industry and manufacturing of these lowlands, owing to the vast amount of cheap, mostly uninhabitable land for the taking.