A recent study has been published in Journal Science. The study revealed that water entered the inner solar system much earlier than that predicted by the scientists. It revealed that the water entered almost 8 to 10 million years after the birth of our solar system. The age of solar system has been roughly estimated to be about 4.6 billion years.
Earlier it was being speculated that asteroids are responsible to bring water to Earth. Now the evidence revealed that how and when the water arrived at earth. When the water first arrived, the earth would have been almost half of its size. Asteroids having water, known as carbonaceous chondrites, were pulled to the planet due to Jupiter’s gravity. This gravity was basically responsible to draw those asteroids enriched with water, to the Earth.
The team- led by Sarafian and researchers from Woods Hole, the University of Bristol, the University of New Mexico, and the American Museum of Natural History- studied the remains of asteroids in order to determine their conclusions.
The lead researcher Adam Sarafian, a Ph.D candidate studying geophysics at the MIT/Woods Hole Oceanographic Institution Joint Program in Massachusetts said that, “No one really knew when these asteroids brought water. Now we’re putting a time stamp on it”.
These carbonaceous chondrites are the residues from the solar system’s birth. They comprises of organic compounds, gas, dust and 22% water which is the critical ingredient for the origins of life.
Earth would have been much smaller then, a fiery rock constantly bombarded with asteroids. But over time, volcanic activity would have released vapor that condensed as the planet cooled. The atmosphere would have thickened enough due to the vapor to allow water on the Earth’s surface.
The evidence was not so easy because Earth has a tendency to recycle rocks because of plate tectonics. The researchers had to depend on eucrites, provided by the Smithsonian, NASA and American Museum of Natural History. Eucrites are a type of meteorite having a phosphate-rich mineral apatite.
What they studied was the amount of water in apatite . Through this knowledge they deduced that almost how much time ago these asteroids came to Earth. Using the ratio of deuterium-hydrogen, they compared the asteroid water and water from Earth. Moreover the Sarafean thinks the next step would be to get an idea of the amount of water in the asteroids.