General Science & Ability

The controlled biological decomposition of organic materials into a nutrient-rich soil amendment

Nitrogen and phosphorus

Excessive nutrient enrichment of water that can cause algal growth and oxygen depletion

It absorbs most of the Sun's harmful ultraviolet-B radiation

Total solar eclipse

Earth passes between the Sun and the Moon, causing Earth's shadow to fall on the Moon

The photosphere

Titan

Ganymede

Phobos and Deimos

The removal and transport of soil by agents such as water, wind, ice or gravity

Molten or partially molten rock beneath Earth's surface