Video Lessons
Where Did Earth’s Water Come From
The article explains that Earth’s unique water composition, with its 70% liquid water surface, is peculiar given what we know about the formation of our solar system. The early inner solar system was too hot for water to exist, so scientists believe that Earth’s water must have come from meteoroids or comets that originated in the outer solar system where frozen water could survive. The most likely source for Earth’s water is carbonaceous chondrites, a type of meteorite that contains water and has similar levels of heavy hydrogen to Earth’s water.