Water on Earth May Not Have Come From Comets

Data from the Rosetta probe shows that water on Earth did not originate from comets as previously assumed, but may have come from asteroids.

Image captured by Philae on the surface of the comet on November 13. Photo: AFP

Chemical analysis of water samples from Comet 67P/Churyumov-Gerasimenko showed that it contained three times more deuterium than hydrogen in water molecules on Earth. Deuterium, also known as heavy hydrogen, is a stable isotope of hydrogen. Out of every 10,000 water molecules on Earth, three molecules contain the heavy hydrogen isotope.

According to Reuters, this discovery eliminates the possibility that water on Earth originated from comets, and opens up a new research direction focusing on asteroids.

"Asteroids may have had more water than they do today. They have existed in the region close to the Sun for 4.6 billion years," said expert Kathrin Altwegg of the University of Bern, Switzerland.

The European Space Agency (ESA) probe landed on the surface of comet 67P/Churyumov-Gerasimenko on November 12, after a 10-year journey. According to initial data, the Philae robot detected traces of organic molecules containing carbon atoms, which are the basic elements of life on Earth.

Comet 67P/Churyumov-Gerasimenko was discovered in 1969. It is 4 km in diameter and lies about 500 million km from Earth.

According to VnExpress