#birrin project

Old sycans drawing

Name: Chriirah

Radius: 0.95 R⊕

Mass: 0.86 M⊕

Gravity: 0.95g

Inclination to Star Equator: 5.389

Axial Tilt: 3°

Rotational Period: 29 Earth hours

Orbital Period: 408 Earth days

Orbital Position: 4th planet, outer Habitable Zone

Distance from Star: 0.965 AU

Magnetopause: 11.4 R⊕

Planetary Temperature: 81°F (27°C)

Satellites: 2 natural

Kahirah, larger moon in clockwise equatorial orbit closer to planet Male, captured asteroid in counterclockwise polar orbit farther from planet

Primary Biomes: Tropical jungles, arid salt flats, canyons, semi-arid savannahs, sandy deserts, temperate oceans, tropical oceans

Description: Similar in size and density to Earth, though slightly smaller, Chriirah is by comparison a hothouse world presently dominated by heavily eroded continents and vast, ice free oceans.

Atmosphere Composition:

Nitrogen 83.03% Oxygen 15.21% Carbon dioxide 1.04% Argon 0.68% Trace gases 0.04%

System Name: K'ati

Star: Red-orange K-type

Stellar Mass: 0.57 M☉

System Features: 3 Neptunians, 2 Venusians, 1 Mercurial, 1 Terran (4 terrestrials, 3 gas giants)

System Organization:

Neptunian → Neptunian → Neptunian → Chriirah → Venusian → Venusian → Mercurial → Star

Galaxy: Milky Way

Distance from Solar System: 4.3 light-years

History:

Chriirah was formed from the protoplanetary disk of its host star while it was still young, the debris within the disk colliding with each other over billions of years eventually forming the planet.

Amidst formation, Chriirah was struck by a large space object, the force of the impact shattering the object and parts of Chriirah's mantle, and sending the debris into orbit. This debris eventually coalesced and formed the larger moon of Kahirah. This impact also reduced Chriirah's axial tilt. Later in Chriirah's history, a small asteroid became trapped in the planet's gravitational pull, becoming the second moon Male.

Life began to form once Chriirah's volatile Hadean period calmed. Chriirah took a shorter time than Earth for its life to become multicellular, only taking 2.8 billion years for unicellular life to make the jump to multicellular.

Approximately 90 million years ago, a stray gamma ray burst brushed Chriirah from a few thousand light-years away, resulting in a mass extinction event similar in magnitude to the Great Dying extinction event on Earth. Over 96% of all multicellular Chriirahan life was destroyed, and the runaway greenhouse effect that had come about by the decomposition of so many organisms caused the previously massive polar caps to melt, flooding the world with rushes of freshwater. This weakened thermohaline circulation by reducing the salinity of the water and oxygen could no longer reach deep ocean currents. This killed 89% of all the remaining microbial life who needed the salt to osmoregulate, and also severely affected aerobic microorganism populations who could no longer get the oxygen they needed for respiration. Overall, nearly 91.4% of all Chriirahan life had gone extinct within a few centuries.