Tetro



Tetro is a terrestrial planet located in the Harani Nebula, a helium- and hydrogen- filled dark nebula near the center of the Tevral Galaxy. It orbits the star Stella Fortuna roughly 170,000 light-years from the galactic core. Tetro exists within the same causally-interconnected universe as Earth, but it is 22.5 billion light-years away, placing it 8.8 billion light-years outside Earth's visible universe. 82% of Tetro's surface is covered in water, while the other 18% consists of seven continents: Gamiala, Reldiga, Narrelia, Venria, Zorvalgia, Calvesia, and Terrelia. It has an atmosphere composed of nitrogen, hydrogen, and oxygen that is contiguous with the surrounding gases of the Harani Nebula. At 2,193,024 miles in diameter, it is 21,182,048 times larger than Earth by volume and has 76,695.6 times as much surface area. It is the only planet apart from Earth known to support life. Tetro is home to 16 intelligent species with a total population of over 12 trillion.

Geologic History

 * See Main Article: Geohistorics

Tetro was formed approximately 5.2 billion Earth-years ago from coalescing dust and gas following the cloud-collapse that created Stella Fortuna. By 4.8 billion Earth-years ago, Tetro's surface had cooled and its clouds, composed of hydrogen and oxygen, rained down water on the surface, forming the planet's oceans. Very little has changed geologically on Tetro since this time. It retains a molten core, but its crust is too thick for tectonic plates or volcanoes to form.

Biological History

 * See Main Article: Biohistorics

The history of life on Tetro began approximately 4.1 billion Earth-years ago on the continent of Reldiga when carbon-based self-replicating molecules formed into protocells in Parova Canyon. Sheltered from the elements by tall overhanging cliffs, the protocells grew in size and complexity over many generations, eventually undergoing a process of organelle differentiation. These early organisms absorbed vital minerals from the rocks and sand on the lake shore, and took in sunlight for energy.

These evolved into Tetro's various life-forms over the following 3.5 billion Earth-years.