What is the primary source of energy for Earth?

The primary source of energy for Earth is the Sun. Solar energy drives many fundamental processes that sustain life and shape our planet's climate and weather patterns. Plant photosynthesis, which converts solar energy into chemical energy, forms the basis of food chains and ecosystems. Additionally, solar radiation influences atmospheric dynamics, ocean currents, and weather systems, playing a crucial role in maintaining Earth's temperatures and supporting all forms of life.

Other sources like geothermal energy contribute to the planet's energy budget but are not as significant on a global scale. The Moon primarily influences Earth through gravitational effects, such as tides, but does not provide energy in the way the Sun does. The Earth's core generates heat primarily through radioactive decay and residual heat, which affects geological processes, but again, it is not the main energy driver for most biological and climatic systems. Thus, the Sun stands out as the predominant energy source for Earth.