Origin of Water in Earth and Space

Recently China's Chang'e 5 lunar lander at its landing site on the moon detected water, becoming the first spacecraft to do so. India’s Moon mission, Chandrayaan-1 had detected water on the moon from orbit & subsequent space missions had mapped water from orbit but China became the first to find water at its landing site near Oceanus Procellarum on the moon's near side.  

India will be launching its Chandrayaan-3 mission in mid-2023 mostly. The space origin of water on planet earth has been corroborated by several studies. Scientists believe that water came to earth through asteroid/meteorite impacts. Meteorites contain water bearing minerals which are full of water and hydroxide molecules. This could be the basis of water delivery to other planets too. Studies have also shown that the same rocks which formed the earth also delivered water to  earth, an action which might have happened around 4.5 billion years ago. . 

We read in our geography lessons that oceans formed due to ice age melting & Rivers come from upstream origins flowing to downstream sea level. While some rivers originate from an existing water body, some have unknown origin but derive  from a single point whereon they are joined by other streams of water flowing downstream till the merge to become a mighty river. In many places, the water at the origin has more mineral nutrients than downstream water. In several such river origin places, Sivalingas have been built like in Trimbakeshwar. 

The asteroids which reached earth nearly 4.5 billion years ago contained ice as some studies done on old  asteroids have shown. Asteroids that bombarded the earth millions of years after Earth formation do not have water. They were found to be dry. So water was formed by the asteroids that reached earth when the planet was formed. This was concluded by research done by Tohoku University in Japan. In other planets like Mars,Jupiter, Saturn, water is in frozen form or believed to be underground unlike Earth which has large bodies of water on its surface. 

Research done by Brown University Geochemist Alberto Saal noted that “ "With a good degree of certainty, we know that the water came to the moon and Earth from primitive meteorites now located in the outer parts of the asteroid belt". Saal and his colleagues published their findings in the journal Science. Saal believes that Earth from its birth had water and that the moon got it from earth when it was formed 100 million years after Earth formed. ution of organic molecules in the early solar system," he said.

In another study done by France’s  Centre de Recherches Pétrographiques et Géochimiques, Laurette Piani, a cosmochemistry researcher and his team studied Enstatite Chondrite(EC) meteorites and concluded that it contained hydrogen more than previously estimated. Piani’s team proposed that “the water present in the Earth’s mantle was directly inherited from EC-like material and present from the beginning of the Earth formation, while the surficial water (oceans) could be made out of about 95% of EC-like material and 5% of hydrated asteroids”. 

Some other scientists differ on this saying that water on earth might have come from comets. In Indian Mythology, we have Ganga coming down from Heaven.There are stories of different gods being born as different rivers. This could be an allegory to an event that might have happened billions of years ago but how did Indian mythology writers conclude thousands of years ago that river water had its origin in space while scientists are discovering that right now through study of these asteroids from space. These texts are supposed to be written around 4000 yrs ago. How then did they deduce water’s space origins since even comets coming to earth might have happened millions of years ago. 

Some studies say that ocean water was always sweet but became salty since rivers started flowing into it carrying along with them minerals along its path. Some locations in the ocean have sweet water where freshwater flows into the sea. During the rainy season when there is huge fresh flow of river water into the sea, ocean water turns sweet as was witnessed by Mumbai residents in 2006. The Lapland Sea is considered to be the sweetest sea on earth since seven rivers drain into it diluting the salinity. Lapland Sea freezes due to low salt levels & low temperatures in the winter months. 

Recent research done while drilling for oil also found fresh water aquifers at continuous stretch from 600-1200 ft below the Atlantic ocean. Scientists from Columbia University and the Woods Hole Oceanographic Institution measured the way electromagnetic waves traveled through fresh and saline water and thus the researchers mapped out fresh-water reservoirs for the first time. When the ice age started, sea levels receded. After the ice age ended, the glaciers melted and sea water level rose. These pockets of fresh water were thus trapped under the ocean.

Uma Maheswar Desu, M,A (History), B.Tech, CIP, CLC,CMSLC, PGDIP, NISM.