Is the asteroid impact theory only responsible for the presence of water on the earth? Why/Why not?
Now days asteroid impact theory only responsible for the presence of water on the earth.Because only that theory is explanatery.
Comets, trans-Neptunian objects or water-rich meteoroids (protoplanets) from the outer reaches of the asteroid belt colliding with Earth may have brought water to the world's oceans. Asteroids may have been primarily responsible based on several studies, including measurements of the ratio of the hydrogen isotopes deuterium and protium, since similar percentage impurities as in carbon-rich chondrites were found in oceanic water, whereas previous measurement of the isotopes' concentrations in comets and trans-Neptunian objects correspond only slightly to water on Earth.In January 2018, researchers reported that two 4.5 billion-year-old meteorites found on Earth contained liquid water alongside a wide diversity of deuterium-poor organic matter.