The planet Tau lives on is called Kraithong. It's named for a Thai folktale about a crocodile named Chalawan, which the star system is named after.

Kraithong is not technically a planet - it's a moon orbiting the large gas giant called Taphaothong. Kraithong is a relatively large, rocky moon with about 70% of Earth's surface gravity, an orbital period around Taphaothong of about 10 Earth days, and a mostly icy surface.

The Sky

Standing on the equator during the day, Taphaothong with its swirling gray, brown and green clouds, fills a large portion of the sky. It's usually a fairly clear view as well, for several reasons.

• The atmosphere is relatively thin - about the equivalent of 6000ft above sea level on Earth. This is thinner than most inhabited planets, so it's fairly common for visitors to require several days of adjustment with supplemental oxygen.
• Due to the composition of the atmosphere, starlight isn't scattered as strongly, with most of it passing through to the surface.
• Chalawan's light is shifted slightly more reddish, meaning there's less blue light to scatter in the atmosphere.

The result of all of this is that, for most of the day, it's possible to look up into the blackness of space. When Chalawan is at its highest point during the day, the sky has a faint blue tint, getting stronger toward the horizon, but even then, brighter stars can still be seen.

Eclipse Days

Kraithong orbits Taphaothong roughly in alignment is the solar orbital plane, which means as it orbits Taphaothong there's a regular extended solar eclipse over the entire moon. In every ~10 day orbit, Kraithong spend nearly an entire day in full darkness because of this. The residents often call this "eclipse day", and it frequently affects scheduling and the general flow of life. In addition to general darkness, the temperature can drop significantly, making this an inconvenient time for many. Events are typically scheduled outside of eclipse days and non-essential businesses and organizations often close their doors.

Geography

Kraithong is a fairly cold moon. It's habitable near the equator mostly due to the reflected sunlight off of Taphaothong, as well as shifts in the moon's crust from tidal forces. Toward the poles, ice sheets grow many kilometers thick as temperatures get as low as -120 C. The entire population on Kraithong lives in the much nicer equatorial region where melt water from the glaciers creates small rivers, streams and lakes. With some light terraforming, this region became a fertile ground for vast forests.

The Colony

The Kraithong colony officially encompasses all inhabited regions of the planet, but the population is divided between one large, urban center and a collection of dozens of small towns on the periphery of the center. This urban center is what residents typically refer to as "the colony".

Entry to the planet is typically handled by one of three spaceports. The largest of these is nestled right in the heart of the colony and is typically reserved for large passenger ships. The other two ports are situated on opposite sides in suburban regions. These handle smaller, private ships as well as most cargo transport.

Structure

Society on Kraithong is similar to that of other inhabited planets. The population is divided into mostly self-governing communities typically including several hundred to several thousand residents, though some dense urban communities can reach the tens of thousands. Each community pools its resources to provide for its residents and other nearby communities. Groups of communities, called regions, meet frequently to coordinate trade and distribution of goods and services to ensure each community has what they need to meet residents' needs. Groups of regions are simply called a colony. Each of these levels, communities, regions, and colonies, handles projects of different scales for its residents.

• Communities handle distribution of housing, food, most public spaces and cultural enrichment. Nearly every community has an office to distribute living spaces. If you need a place to live, you can walk in and request a place, either temporarily or permanently, and they will find a place to meet your needs. Most grocery stores, markets and farms are run by communities to distribute food free of charge.
• Regions handle more complex system, such as larger scale utilities and facilities. Power grids, sewers, hospitals, universities and some public transit systems all under their jurisdiction.
• Colonies oversee projects that would affect the entire planet, such as the spaceports on Kraithong, but more so colonies manage the integration of regional projects. Each region may build their own power infrastructure, for example, but it's important to ensure each region can connect to each other effectively.

Most importantly, any sort of animosity toward other communities or regions or colonies is an outright taboo. Everyone collectively helping their neighbors doesn't work if some neighbors are seen as less worthy. These systems allow all residents unconditional access to any necessities, such as shelter, food, water, healthcare and anything else they need to live a happy life.

Technology

The average person on Kraithong has access to very advanced technology by 21st century standards, but the amount of advanced technology in their immediate vicinity isn't significantly higher than in the early 21st century. Most residents don't need (or want) full home automation, robotic assistants, or a flying car. The really advanced stuff belongs to the community, rather than the individual, such as anti-gravity shuttles, medical technology that can diagnose and cure most issues in minutes, and printers that can replicate nearly any object down to the molecular level.