Atmosphere and Biosphere Grades

Atmosphere and Biosphere Grades serve as essential components of a planet's classification system, providing a comprehensive evaluation of the state of a planet's atmospheric and biospheric conditions. These grades are instrumental in determining a planet's habitability, potential for colonization, and overall environmental suitability.

The Atmosphere Grade assesses the composition, density, and overall quality of a planet's atmosphere. It takes into account factors such as oxygen levels, presence of greenhouse gases, and atmospheric pressure. A higher Atmosphere Grade indicates a more Earth-like and conducive environment for human habitation, while a lower grade might imply conditions that require extensive terraforming or life support systems to sustain life.

The Biosphere Grade, on the other hand, evaluates the diversity, complexity, and health of a planet's biosphere. This encompasses various aspects of ecosystems, including flora, fauna, microbial life, and the overall ecological balance. A higher Biosphere Grade signifies a thriving and diverse biosphere capable of supporting complex life forms, while a lower grade suggests a less developed or potentially even barren environment.

Together, the Atmosphere and Biosphere Grades offer a holistic understanding of a planet's environmental conditions and play a pivotal role in determining its classification within the broader celestial catalog. These grades aid in strategic decision-making by providing insights into a planet's suitability for colonization, resource extraction, and potential long-term viability as an asset within the Thoria Empire's broader expansion and development efforts.

## Atmosphere Grades

### Grade I

A planet with a Grade I atmosphere is characterized by the absence of any discernible atmosphere. This grade is typically associated with celestial bodies like asteroids and barren moons, where atmospheric conditions are negligible. To exist in these environments a full environment suit is required.

### Grade II

A Grade II atmosphere indicates a very thin and tenuous presence of gases. The atmospheric pressure is exceedingly low, making it challenging for complex life forms to thrive. Planets in this category often require extensive terraforming or life support systems to make them habitable. To exist in these environments a full environment suit is Advised but a breath mask would suffice.

### Grade III

A Grade III atmosphere suggests a more substantial composition of gases, but still falls short of the ideal conditions for human habitation. Atmospheric pressure might be marginally suitable for certain forms of life, but terraforming efforts would likely be needed to establish a sustainable environment. A full environment suit is no longer required or advised but a breath mask is.

### Grade IV

A planet with a Grade IV atmosphere possesses conditions that are closer to Earth's atmosphere in terms of composition and pressure. While not yet considered ideal for human settlement without modification, Grade IV atmospheres offer a higher potential for terraforming to create a habitable environment. A breath mask is required for any long term stay but is otherwise optional for short bursts.

### Grade V

A Grade V atmosphere represents the pinnacle of atmospheric conditions. It closely resembles Earth's atmosphere in terms of composition, pressure, and oxygen levels. Such environments require minimal to no terraforming and can support a wide range of complex life forms, including humans, without significant adjustments. No breathing apparatus is required or advised.

## Biosphere Grades

### Grade I

A Grade I biosphere indicates a complete absence of life. The planet lacks any form of organic or biological activity, making it a barren and inhospitable environment.

### Grade II

A Grade II biosphere suggests the presence of basic microbial life or very simple organisms. These life forms may exist in extreme conditions but do not contribute significantly to a functioning ecosystem.

### Grade III

A Grade III biosphere signifies the presence of more complex and diverse forms of life, including plants, insects, and basic animal species. However, the overall biodiversity and ecological balance may be limited compared to more advanced biospheres.

### Grade IV

A Grade IV biosphere indicates a thriving and balanced ecosystem with a wide range of species, including complex animals and higher-level plants. Biodiversity is robust, and the planet's various ecological niches are filled by specialized organisms.

### Grade V

A Grade V biosphere represents the pinnacle of biological diversity and complexity. The planet hosts a rich array of ecosystems, including intricate food webs, symbiotic relationships, and adaptable species that have evolved to thrive in various habitats.