Extraterrestrial Life Organic Molecules Building Blocks of Life Water on Earth Extraterrestrial Environments Organic Compounds Conditions for Life Extraterrestrial Water Chemical Signatures Nutrient Cycling Environmental Changes RNA Primitive Life Forms Terrestrial Hot Springs Extraterrestrial Materials Cosmic Materials Chemical Processes Chemical Building Blocks Chemical Reactions Mars Exploration Delivery of Organic Material Seeds of Life Carbon-Rich Asteroids Water-Bearing Clay Minerals Water Delivery to Earth Carbon-Based Life Seeding from Outer Space Essential Ingredients Building Blocks Extraterrestrial Impacts Prebiotic Chemistry Early Earth Conditions Life Beyond Earth Hydrothermal Vents Asteroids and Water Extraterrestrial Chemistry Water Distribution