Eylhrene

Eylhrene is a ringed planet far far from Earth. The main orbits at high metallicity star slightly bigger than the sun at a mean distance of 190 million kilometers, but with a margin of fifteen million kilometers eccentricity. Eylhrene was impacted fairly recently in geological history by a lunar sized object, which resulted a 90 degree acial tilt, two large moons and a ring and day-night cycle of 14 hours. As a result, the planet experiences extreme seasons and extreme coriolis effects and quite significant tides in autumn and spring. The planet is equivalent size to Earth. To exacerbate the seasonal variation, the system in which the planet orbits is a twin star system – the secondary star is effectively a red dwarf orbiting the main star at a distance of just under one billion kilometers. In effect half the year the planet is bathed in a dull sheen many times the luminosity of the moon. This illumination isn’t red, but is very dense in the infrared and does warm the winter size cyclically.

So in effect the planet has the most extreme seasonal variation possible – an eccentric orbit, 90 degree axial shift and a dense ring. But that isn’t what makes the planet so markedly different than Earth.

The planet has a very dense atmosphere and major variation in surface altitude. Relative height difference on Earth is from the deep Mariana trench (-11 kilometers median to sea lavel) to the Himalaya peaks (+8 kilometers median to sea level) which makes for a variation of 19 kilometers. On the planet Eylhrune this variation is 28 kilometers, and the planet has a lot more atmosphere, and just under 10% of the planet is covered in sea. From a human perspective the entire planet is covered in a dense layer of roiling clouds. Only 4% of the planetary surface is above the clouds and effectively habitable to humans. Over a billion years ago much of the rings around Eylhrene slowly rained back on the planet in an equatorial band, and in effect half the habitable plateau regions that rise from endless roiling clouds are situated in a tight band around the equator. Under the clouds this band extends as a titanic mountain range along the full equator. The biggest island plateau, east to west, extends only 600 kilometers equatorially and is just over two hundred kilometers at its widest north-south width.

Eylhrene is a beautiful planet from orbit. It is a deep golden planet illuminated from its main sun in its summer, and has a distinctive brandished coppery taint on the winter side. In autumn and spring the planetary clouds attainst a deep tan beer color, with distictive coriolis storms streaking the higher lattitutes, especially in deep winters. The year is longer than on Earth, with a full 450 days, and a lot of energy deposited by the sun on this fairly high albedo planet tries to migrate to the other end, which means massive cloud migrations which are in turn whipped in to vicious coriolis storms. These storms do cross the equator.

The effect of the rings is marked. The rings are composed mostly of carbonaceous black material and quartz, making them look pale rusty red. This has the effect that in mid summer they reflect quite a bit of light and cast it back along the illuminated hemisphere, increasing illumination. As the planet then tilts back, for many months as the nights re-emerge, the nights are cast in a deep red hue as the rings reflect a lot of light back on to the planet. But on higher lattitudes as the nights get longer, the rings attain a more ominous red shade and the clouds are bathed in a deep blood red hue due to filtered refraction, and storms bathe and lash the nigh half of the planet. These storms are more extreme as the planet is furthest removed from its main sun, and the night side is not illuminated by its distant secondary star.

The planet might look little inhabited by life, but it is much more alive than Earth. Relative to Earth median air density, the planet has small scattered seas (more large lakes) that lie at a depth a full twenty two kilometers deep, in eternal thick roiling clouds. Very few humans have ever seen the sees of Eylhrene, and they are said to be pitch black and very salty. But everywhere on the planet is a thick endless cover of jungle, from pole to pole, and the atmosphere of Eylhrene is saturated with microcellular organisms with a natural buoyancy, as well as endless forms of cloud life. In fact half the jungles do not survive on photosynthesis at all – the atmosphere of Eylhrene is one giant photosynthetic machine far more productive than Earth. In comparison to Eylhrene, Earth is mostly barren desert – Eylhrene has several times the effective biomass as Earth does.

But this life down there is a hardy and resilient life. Even though the Coriolis storms do not fully penetrate in to the depths of the cloud bottoms, endless rains do. Furthermore temperatures down below are quite high in summers, due to a strong greenhouse effect, high pressure and extreme humidity. Atmospheric pressure at “sea level” is a full ten Earth median, and temperatures are close to 100 degrees Celsius – however at those pressures that deep (and with the way the atmosphere is composed) the boiling point is close to 200 degrees.

In effect the planet Eylhrene has three distinctive layers atmospheres – the upper layer is just like Earth, with normal clouds and a sky. The second layer is defined by being permanently overcast and commences at about 1.6 atmosphere. This is where the atmospheric life takes hold and the access to sunlight sharply decreases as one descends. At a relative depth of about 3 atmospheres all photosynthesis ends, but most every inch is covered by massive jungle and morass. There is a lot of animal activity going on at these depths. A half kilometer lower, at 4.5 atmosphere the nature of organisms quickly changes and very few animals survive, and the atmosphere becomes toxic to humans. That comprises about 40 percent of the planet.

In these lowlands the temperature differential between winter and summer is massive – close to a hundred degrees Celsius. Still, it never snows in the depths of the sunless seas, but it does occasionally storm, and quite often vortices and tornadoes touch down on to the surface.

Most humans on the planet Eylhrene live not far from the equator, as life along the northern and southern latitudes is simply not possible in winters. Those plateau regions that rise above the atmosphere situated at over 15 degrees north and south are drenched in deep snow, while in summer they are quite warm.

One final mention is relevant to the tides of Eylhrene. The planet has two moons, one at 200.000 kilometers, and a little bigger than the Earth’s moon, and one at 400.000 kilometers and more or less identical to the Earth’s moon. Both are tidally locked. The interplay between these two moons causes considerable tides on the planet, especially in atumn and spring, as the moons exert pull in tandem with the sun. If the planet, sun and both moons line up, the tides on the planet can cause the atmosphere to rise up and engulf some minor islands along the equator for hours in thick roiling clouds and torrential rain.