What three conditions are planetary science focuses on for life as we know it?
Liquid water, energy sources, and correct chemical building blocks
The search for extraterrestrial life necessitates a focus on environments that replicate the essential requirements for life as it is understood through terrestrial biology. These prerequisites are universally recognized as liquid water, which serves as the universal solvent necessary for biochemical reactions; a source of energy, which can come from stellar radiation or internal geothermal/chemical processes; and the presence of the correct chemical building blocks, such as carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur. Planetary science missions are specifically designed to characterize environments, such as the subsurface oceans of moons like Europa or Enceladus, or ancient surface features on Mars, to confirm the existence of these three foundational elements necessary to foster life.
