Sci-Fi Writers' Club Worldbuilding
PLANET EPIMETHEUS
The Epimetheus Project is an ongoing attempt at creating a completely realistic alien world and the creatures that inhabit it. It was started in the 2003-2004 schoolyear, during which time the structure of the solar system and basic geography of the planet were worked out, along with a small number of aliens and the environments in which they lived. From this data, Logan was able to flesh out the details of climate and meterology, and fill in the biomes of most of the world. As of 2nd
Three Ages of Life are planned for Epimetheus, starting with the Second Eon, so as to be able to fit in lots of cool aminals and show the progression of evolution. However, as we have a good 3.5 to 4 billion years of main sequence lifetime left in its star at the beginning of the Second Eon, it's quite possible to come up with intermediate stages of continental drift and evolution, and fill in the timeline with as many unique ecologies as we want.
The First Age of Life has the globe sharply divided, and completely different creatures have developed on the two landmasses that are about to meet up. We probably won't place any intelligent creatures here, but the possibility has not been ruled out.
The Second Age of Life will have a bit more break-up going on in the supercontinent. Continental drift patterns have not been fully developed, so we don't know whether or not Antipode will have impacted any part of the Mainland yet. The Second Age will be populated with creatures evolved from the First Age. This is the first place where we will put a Great Civilization or two.
The Third Age of Life will be equivalent to post-human Earth. The continents will be greatly altered, a new intelligent species will be introduced, and it will be populated with creatures evolved from the First and Second Ages.
The Star: Kronos (Uranus?) Spectral Classification: F8.5V Surface Temperature: ~6200K Mass (Sol): 1.081 Luminosity: 1.315 Starpower Main Sequence Lifetime: ~8.22 Gy Metallicity (Sol): 1.05 The Planet: Epimetheus System Letter: c Orbital Distance: 1.22AU, 1.8251e5 km Energy Flux (Earth): .88372 Year (Earth): .799 (291.82676 Earth Days) Surface Gravity: 8.5086 m/s^2 Mass: 4.97e24 kg Radius: 6243 km Surface Pressure: 1.3 bars Axial Tilt: 26º
Early after the planet formed, it was impacted by a mars-sized world, similar to the impact that created the Earth's moon. In this case, however, the debris accreted into 4 moonlets. The planet's high rotational velocity initially drove all the moons away, but the stationary orbital radius expanded faster than the orbit of the innermost moon. Once it crossed the stationary orbit, this moon began to fall towards the planet, increasing its rotational velocity. By this time, the other moons had become locked in orbital synchrony, and the entire system had to expand proportionally, such that the inner satellites did not move outward significantly further. At one Gy, the innermost moon hit the upper atmosphere, and its orbit quickly degraded, crashing it into the planet well after the crust had completely solidified. This massive impact threw up mountain ranges on the opposite side of the world and carved an enormous basin on the side of the impact, lowering the average altitude of that hemisphere by several kilometers. Geostatic rebound created a single minor continent around the central peak. When everything settled, the world was left with a supercontinent covering one hemisphere, with a global ocean, broken by the minor continent, covering the other hemisphere. Ring fractures in the global ocean marked plate boundaries, and as they slid about volcanic islands formed a rough ring of archipelagos between the minor continent and the mainland. A large volcanic hotspot in the southern hemisphere, on the eastern edge of the supercontinent, forced up the Australian Bulge, a section of sea crust lifted above sea level by an enormous upward convection current of magma underneath it. On the equator, on the western edge of the supercontinent, a similar upwelling created a formation similar to Venus's Diana Chasma. The extra land created by the Australian Bulge allowed snow and ice to pile up, reducing the average sealevel and slightly increasing the planet's albedo. Combined with the removal of greenhouse gases from the atmosphere by microorganisms, this plunged the world into an ice age. Periodic eruptions of the Australian supervolcano, which melted the ice and introduced large amounts of greenhouse gases into the atmosphere, caused snowball/hothouse cycles lasting approximately ten thousand years each.