Galactic standards

Measurements

The galaxy is a large place, and everything needs to be measured and classified, even considering that each planet has its own native measurement systems.

Planet Classifications

The galaxy classifies planets based on average habitability. Most sentient species are carbon-based and, therefore, have similar needs, such as liquid water and oxygen.

A planet is more or less habitable if one of these criteria is not met. There are also more flexible requirements, such as atmospheric density, but that can often be easily fixed with a simple suit and a breathing mask.

Habitability Type	Description
Type U	Uninhabitable, either due to no atmosphere or otherwise lack of available oxygen or liquid water. This classification is also for super hot planets, where no human can survive without severe heat protection suits.
Type E	Enviromental suit. Pehaps too cold, or slightly too hot. maybe they are the right temperature but the air as acidic, or there is acid rain. Whatever the reason, you need a full suit.
Type O	Oxygen Mask. These planets are the right temperature and have liquid water, but lack oxygen.
Type H	Habitable. You might still need a respiratory mask, depending on your species, but the planet is otherwise habitable and likely already has life on it, since oxygen is rarely found in places without it.

Gravity

Often, when classifying planets, nations will add a gravity indicator. This is important because creatures live best on planets with similar gravity to their home world.

The gravity is a percentage of the galactic standard, which is the planet Kryllix IV, this is because it was the first capital of the Gaactic republic, and they are the ones who codified most of these standardization. Kryllix IV has a gravity of 1. If the number of a planet is 1.11, that means it is 111 percent the gravity of this planet, etc.

Colonization

When colonizing a planet, civilizations always have to do some amount of terraforming, maybe get rid of some toxic gas in the atmosphere or adjust the temperature, but civilizations will only go through all this very expensive and time consuming trouble if it is really going to be worth it.

That is why, in general, those looking to colonize will look for planets with similar climates and gravity to their own planets, preferably one where there is already life living, because that means it is definitely habitable.

Gravity is a less important factor, but airpressure is for some species a very important thing to consider, and even those that can survive a great variety of air pressures, might need to spend time in pressure chambers to get used to higher or lower pressures.

Star

Star classifications are also important, even though they are often left out of planetary classifications. However, the star does have al lot of influence on how the planets surrounding it will be and how habitable they likely are.

There are seven types of main sequence stars, but there are only four which generally support life, this is because the bigger stars rarely live long enough for life to evolve on one of their planets.

White Stars only rarely contain native life, but it isn't uncommon for civilizations to build colonies on planets around these stars due to their general stability. However, they are the least common of the life containing stars.
2% of all stars are of this type.

Yellow Stars are a little bit more common, and a little bit smaller, these stars support a disproportionally large amount of life for their rarity, this is because of their stability, and long lifespans.
3.5% of all stars are of this type

Orange Dwarf Stars are more common still, and they are quite similar to the Yellow stars, they are the second most likely to have life containing planets.
8% of all stars are of this type.

Red Dwarf Stars are by far the most common in the galaxy, but they are also often quite unstable and emit a large number of radiation bursts, which is why their planets don't commonly support life. However, some more stable red dwarfs do have life living on one or more of their planets.
80% of all stars are of this type.

Travel

For the sake of travel, the most used unit of measurement is the Parsec. This is used to calculate the distances between stars, and the distance to be traveled so one knows how much fuel to load up.
Within star systems, the most common unit of measurement is the LightHum, the distance that light can travel in the span of one Zarthanian Hum, a length of time that lasts a bit more than a Terran minute.

Speed

In warp travel, the only measurement that is used is the P/h or parsecs per hour, while sunlight travel is generally measured in a percentage of light speed. For example: 65% of light speed, meaning approximately 702 gigameters per hour. (702.000.000.000)

Time

The are still nations that prefer their own time, but there is a galactic standard time. The exact origins of galactic universal time has long since been forgotten, as many of the galactic records previous to the republic have been either destroyed, or been otherwise lost.

However, the standard days and years can be traced back to Kryllix IV, the original center of galactic civilization.

The galactic standard day is 30 hours, and the galactic standard year is 300 galactic days.

Planets usually still keep track of local days and years, for practical reasons, especially if it has a native species. Colonies will usually have a system of time measurement based on that of the colonizing species, all used in addition to galactic time.