Aine (RS 8409-2269-8-5352807-53 B1 in is an unusually hot E-Class planet located outside the main spiral arms of the Milky Way. It is the only habitable planet in the Dagda System, and orbits the binary brown dwarfs Egobail and Gardicia. Aine was discovered in 2067 by the Irish Space and Astronomical Committee (ISAC) and named after their ancient goddess of love and summer.

In 2167, the 100th anniversary of Aine's discovery, an FTL probe was sent to the system in order to find out whether or not the planet was suitable for colonization. It was discovered that the climate of Aine is too delicate for human presence.

Currently, Aine is under environmental protection by the Confederacy of Humanity.


Aine as seen from ISAC's FTL probe


Aine was discovered in the triple star system Dagda, orbiting the equal-mass brown dwarfs Egobail and Gardicia. It is similar in size to Earth, but has two small asteroid-like moons. The planet is almost 12 billion years old and is teeming with terrestrial and aquatic organisms.


Aine is primarily a forest planet, but has some water. About 75-80% of Aine is forest-covered land, while the rest is the planet's seas. Most of Aine's water is concentrated inside 6-12 giant impact craters left over from its violent past. Each crater is several hundred miles across, with the largest being close to the size of Saturn's moon Rhea. On one hemisphere of Aine, there is a large sea that contains 20-30% of the planet's water. River systems thousands of miles long connect the crater lakes with the major sea.

Most of Aine's water is found on the planet's western hemisphere. The east, however, is mostly a mountainous terrain with the occasional lake or river. Mountains here reach only a few kilometers high because of Aine's higher gravity. However, the western hemisphere has the planet's highest and largest peaks. Several volcanoes dot the areas near the giant sea, and one of them is rising from the water. This volcano is a few kilometers above Aine's cloud tops, providing a much better place to launch spacecraft from.

Weather and Climate

Unlike other E-Class planets, Aine is in the "Hot" category, with an average temperature of 127 degrees celsius. This is caused by the planet's giant volcanoes are pumping a dangerous amount of greenhouse gases into the atmosphere, causing a rise in temperatures. That greenhouse effect has raised the planet's temperature by 113 degrees celcius. The FTL probe sent to Aine revealed that human industry on the planet would tip the scales and lead to a runaway greenhouse effect. However, another race wanted to colonize this planet, which led to the Treaty of Aine in 2405.

Aine's weather and climate seems to match that of Kerhb, another habitable planet orbiting a brown dwarf system. Both are tidally locked worlds, which means that there will be a hurricane on one side. Aine's and Kerbh's storms have a similar planet-to-cloud size ratio. Both planets also have similar stars. But the similarities end there. Aine is much hotter than Kerhb, and also have a more smoggy atmosphere. This planet also has more clouds than its purple cousin.

Despite its hot temperatures, Aine has a very high Earth Similarity Index (ESI) of 0.899. This is probably due to Aine's similar size to Earth and abundance of green planet life. The two planets due share some meteorological features. Aine's atmosphere contains jet streams, which move with the hurricane's rotation. The clouds of Aine are mostly made of water vapor like those on Earth. But because Aine is over 120 degrees celcius, they're also made of Carbon Dioxide, Carbon Monoxide, and Sulfur.

All of Aine's weather is driven by its high temperatures, with the exception of some storms over its seas. The front side hurricane, like most hurricanes on exoplanets, rotates clockwise. It spans from about 4,000 to 6,000 kilometers, or roughly 40-50% of Aine's diameter. Winds near the Eye Wall reach a staggering 315 miles per hour on average. The entire planet has about the same temperature, so wind speed changes are nearly impossible. Clouds farther from the hurricane, however, move at a slower pace because of the larger amount of land they must cross.


Aine is heavily populated by organic, multicellular and unicellular organisms. This means that the creatures here are carbon-based life forms, like those on Earth. Both Aine's terrain and waters are home to life, but terrestrial organisms are far more abundant. Either way, life on Aine is highly varied.

About 13% of life on Aine is marine. The large sea on Aine is home to huge, winged, fish-like organisms. They never fly more than 30 feet above the oceans, but their giant wings prove helpful for swimming in this high gravity environment. These wing-fish are very large and have white skin to reflect as much sunlight as possible. That way, they won't get dehydrated in this hot but habitable world.

Most of Aine's life are plants, or related organisms. Much of this planet is covered in green, even the seas! Green algae float in huge patches on the surfaces of the Ainean oceans. They are the main food source for wing-fish, along with many smaller creatures. Ainean algae give the planet's oceans a slight green tint.

Much of the Ainean landscape is covered in giant forests. They mainly populate weird structures called Shingle Mountains, which are large hills with multiple layers visible from far off. The widespread Ainean forests turn this hot planet into one of the most green worlds in the entire Milky Way.


Unlike Earth, Aine does not need a large "Stability Moon". Aine is tidally locked, so the climate is stable even if the planet has two little captured asteroids. These moons, Ishr and Echor, orbit close to Aine and are easily visible from the surface. However, there orbits are rather tilted.



Echor and Nyyox Cratus

The largest and closest moon of Aine, Echor has a circular orbit that has no tilt. This moon is just under 17 kilometers across and resembles the moon Nix, which orbits Pluto. Both moons are elliptical in shape and have giant craters on one side. Echor's massive basin, named Nyyox Cratus, was formed on one of Echor's "tips". It has a rounded floor and a central peak rising 0.5-1 kilometers into space.

Echor orbits at a distance where tidal forces start to become dangerously extreme. Like Mars' moon Phobos, Echor is being pulled on by its parent body. In this case, Aine is stretching the tiny moon into its ellipsoid shape. The pointy edge of Echor is the side always facing Aine. This moon does have some stress cracks, but the lack of them shows Echor may have 50 million years left before breaking up.



Ishr and the basins Circh and Icholo

At just a mere 9.7 kilometers in diameter, Ishr is the smallest moon of Aine and just half the size of its sibling, Echor. This tiny moon has an orbit tilted by over 90 degrees. Ishr has been subjected to many brutal impacts that scar its surface. At least 3 craters cover and area over 15% that of the moon's diameter. The largest crater, Circh, is similar to Nyyox because of its rounded floor and giant, weirdly-shaped peak.

Like the larger Echor, Ishr is also being pulled on by Aine. Its wildly oblong orbit creates a lot of tidal stress which is stretching Ishr. However, the forces aren't enough to pull Ishr into a football shape. These tidal forces are strong enough to pull one region of Ishr higher than the rest of the moon. It is the area with Icholo Basin, another large crater that is 70% the size of Circh.


Aine has a very circular orbit around Egobail and Gardicia, with a 0.005 degree eccentricity. The orbit also has a tilt of less than a billionth of a degree, rendering it nearly a perfect circle. It is hard for circumbinary planets to obtain such neat orbits, but Aine has had nearly 12 billion years to stabilize. Aine's average distance from its stars is about 6.78 million km, or about 0.08 AU. This puts it outside the habitable zone of its parent stars, but Aine's massive greenhouse effect keeps it warm enough for life.


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