The World

Hemes is the second planet from Astra and the only planet in the planetary system that harbours life.

## Physical Characteristics

Hemes’ structure consists of a outermost silicate crust, a molten silicate mantle, a liquid iron outer core (whose flow generates the planet's magnetic field) and a solid iron inner core. The surface is made up of land in the form of continents and islands, though most of the surface consists of liquid water oceans. Active plate tectonics give rise to both terrestrial and submarine mountain ranges, volcanoes, valleys and plateaus among other features.

### Orbital & Rotational Characteristics

A day on Hemes is about 26 Earth hours long, with Astra rising in the west and setting in the east. Temperate and polar regions on Hemes are subject to moderate seasonal variation in heating due to the planet’s rotational axis being tilted with respect to the plane of the ecliptic. In the tropics, (24.5° south to 24.5° north), Astra is directly overhead for at least one day per year, whereas in the polar regions, (65.5° to 90° north and south) Astra never rises or sets for at least one day per year. Hemes orbits Astra at an average distance of 1.58 AU. Though this distance varies throughout the year, Hemes remains at all times within the system's habitable zone—a region of space stretching from 1.15 to 1.66 AU where temperatures are such that liquid water can exist on its surface.

### Atmosphere & Climate

* The sky of Hemes at noon
* The sky of Hemes at sunrise and sunset
1/2Hemes’ atmosphere consists of mostly nitrogen and oxygen, as well as fractional percentages of carbon dioxide and argon. Atmospheric surface pressure and density are also slightly high, which significantly impacts the local flora and fauna. Hemes’ atmosphere is divided into three circulation cells per hemisphere: a Hadley cell extends from the equator to 30° north and south, a Ferrell cell extends from 30-60° north and south, and a final polar cell extends from 60° north and south to the poles of the planet. At noon, when Astra is at its zenith, the sky is a pale blue colour. Near sunrise and sunset, the sky turns a deep, dark blue colour fading to a golden hue near the horizon.

### Oceans

#### Irisian Ocean

The Irisian Ocean is the second-largest of Hemes' oceans, with an area of about 364,500,000 square miles. It covers approximately six percent of the world's surface occupying a triangular region north and west of Patrída. As one component of the interconnected World Ocean, it is connected in the east to the Vasaric Ocean, to the Solomic Ocean in the southwest, the Ignic Ocean in the north east, and the Agnosic Ocean in the south east.

Originally the name comes from the X tribe who inhabit the majority of land on Oriern that borders the Irisian Ocean. The name of the ocean comes from their belief that the god Iris lives on an island in the middle of it.

## Astra, The Star of Hemes

Astra is the star at the centre of the solar system. It is the most important source of energy for life on Hemes.

### General Characteristics

Astra is a F-type main sequence star (F8.7V). that constitutes over 99% of the mass of the planetary system. It is mostly comprised of hydrogen and helium plus an assortment of various trace elements. Its radius is over 115 times that of Hemes, making it easily the largest object known to humankind. With an absolute magnitude of +4.4, and an apparent magnitude of -26.78, Astra is by far the brightest object in its stellar neighbourhood and the brightest object in the sky of the Hemes.

### Formation & Life Cycle

Astra formed approximately 3.5 billion years ago, with Hemes itself forming approximately 3.4 billion years ago. Astra is approximately four-fifths of the way through its main-sequence lifespan. It will continue to grow larger, hotter and more luminous over the next 3.087 billion years until it finally exits the main sequence, becoming a giant star and thereafter a white dwarf. Hemes will not survive after Astra exits the main sequence.

### Planetary system

The Planetary system is a four planet system, it is divided into two broad regions; the inner region and the outer region. The frost line at 5.869 AU demarcates the two regions

#### Inner Planets

The inner planetary system is the domain of the rocky, terrestrial planets. Two major rocky planets orbit in the inner system: Planet A and Hemes. Planet A is small, rocky, lifeless world

orbiting close to Astra, whereas Hemes orbits further out within the habitable zone (1.15 - 1.66 AU), thus making it the only planet in the planetary system capable of harbouring life.

Models of the planetary System predict the existence of an additional planet, orbiting at ~2.64 AU; however, no such planet exists.

#### Outer Planets

The outer system, beyond the frost line, is the domain of the large, gaseous worlds. Two major gaseous planets orbit in this region: Planet C and Planet D. Planet C is the largest planet in the planet system, while Planet D is intermediate in size between Hemes and Planet C. Both worlds are orbited by multiple moons and have tenuous ring systems.

#### Asteroid Belt & Debris Disk

Between the orbits of Hemes and Planet C, lies the asteroid belt; the main portion of which extends from 3.3 AU to 5.29 AU. Dwarf Planet A, a minor dwarf planet, orbits within the

belt at ~4.6 AU. Beyond Planet D, lies the icy debris disk which stretches from 41.2 AU to 49.91 AU. Many small dwarf planets orbit within the debris disk, most notably Dwarf Planet B at ~41.25 AU. Humankind is currently unaware of the existence of these objects.

## Orbital Bodies of Hemes

Hemes is orbited by two natural satellites, which due to their angular size give rise to different pairs of total and annular eclipses. The largest of Hemes' natural satellites causes tides.