The worldWhile the origin of water on Earth has long been a matter of debate, this discovery now provides evidence that water came to our planet from asteroids in the outer solar system. According to one theory, the Earth was barren when it formed because the inner region of the solar system was too hot for water to condense. Scientists think that water may come to Earth later from frozen meteorites. While the ratio of hydrogen isotopes found in the water in the meteorite was determined to be very similar to the composition of water on Earth, this finding proves the theory that asteroids contribute significantly to the water on Earth.