What is the term for the total amount of water on a planet?

The total amount of water on a planet is referred to as the hydrosphere. This term encompasses all water found on, under, and above the surface of a planet, including oceans, rivers, lakes, groundwater, and ice. The hydrosphere plays a crucial role in various planetary processes and ecosystems, influencing climate, weather patterns, and the distribution of life.

In contrast, the abyss typically refers to deep oceanic zones rather than the overall water content of a planet. The geosphere pertains to the solid part of the Earth, including rocks and minerals, while the atmosphere is the layer of gases surrounding a planet. Understanding these terms helps clarify the components that make up a planet's environmental system, particularly the distinction between the different spheres and how they interact with one another.