In addition to galactic-scale phenomena such as the spiral arms, the Core, and the Barriers, many dangers and scientific opportunities appear in the vast empty spaces among the stars. In general, such phenomena occur most commonly in regions of denser star populations, but exploratory vessels have found enough excep-tions to this rule to fill a
Spectral (or stellar) classification is the process by which scientists define the size, composition and emissions of a star or other astronomical object. The system begins with a series of letters followed by single digits that determines the star’s heat and output. Additional symbols and abbreviations are added to further qualify special types of stars
The Federation classifies planets it catalogs based on criteria such as atmospheric composition, surface temperature, and conditions, the size of the body, and the presence of animal and plant life. This system is used to determine the suitability of the planet for exploration, colonization, and scientific research. Each class of planet is assigned a letter
The Galaxy is not an undifferentiated mass of stars, but contains many different features and regions. Each has its own challenges, opportunities, and dangers for interstellar explorers, colonists, and scientists. The Spiral Arms Like other space objects, the Galaxy rotates, creating “spiral arms” thousands of light-years long and thick; each arm contains thousands of stars.