Water on Earth came from space? Here is a new interesting study

Water covers about 71% of the Earth's surface. There is water in the seas and oceans, rivers and lakes, there is some water trapped in rocks beneath the surface, there is water frozen as glaciers, and there is water existing as vapour in the atmosphere.

And we, human beings, are about 55 to 78% water.

Now, scientists say water on Earth may not have originated here, but was brought to our planet by asteroids from the outer edges of the solar system. Scientists from Japan and other countries say this after analysing rare samples collected on a six-year Japanese space mission.


In a new paper published in the journal Nature Astronomy, scientists say samples from an asteroid called Ryugu could give clues to the mystery of how oceans appeared on Earth billions of years ago.

"Volatile and organic-rich C-type asteroids may have been one of the main sources of Earth's water," AFP quotes the study, published in the journal Nature Astronomy, as saying.

They hypothesise that such material may have even come here from outside our solar system. Though that could not have been the only source.

Their studies are on rocks and dust drilled from Ryugu by the Japanese space probe Hayabusa-2, which is the most 'uncontaminated' material from the solar system available to us.

The studies are being published one by one - an earlier study in June suggested that organic material which showed that some of the building blocks of life on Earth, amino acids, may have been formed in space.

All these findings beg the rather existential question: How much of us is alien on Earth?