The source of Earth’s abundance of water has long been an issue of debate among scientists. Some of these claims were based on the idea that our water is something intrinsic to the Earth--in other words, the Earth came with its own water. Others suggest that water came from outer space, using meteorites as a medium for travel. A recent discovery has managed to confirm the latter.
It was announced on June 27th at the National Astronomy Meeting in Nottingham, England, that a meteorite that had all the answers was dug up in Antarctica. Named Meteorite EET 83309, the space rock was found under the thinning ice of Antarctica. After a few scans, scientists were able to find out that the meteorite had opals on it. Opals are minerals that have water as a good portion of their composition. What’s more to say, the opals were not from Earth, meaning that the water inside them was also born in space. This ground-breaking discovery is solid evidence that could demonstrate that in the younger years of the Solar System, [water] ice was sometimes carried by meteorites onto other celestial objects.
Opal is a unique mineral in and of itself, at least when it comes to what it comprises of. Other than being one of the most common minerals on Earth, it's made of 30% water on its surface. How? Opal is made of a substance called silica (like sand) and as stated before, water. When water moves across sand, it takes in silica and leaves behind the materials to make opal. When the water evaporates, it leaves behind the minerals to build opal – which is how water built up in this continuous cycle.
Unfortunately, Meteorite EET 83309 is the only extraterrestrial object discovered to have opals from space.
After a thorough investigation, the full analysis report confirms that the opals present did not form under Antarctica's ice. Two pieces of evidence led to this conclusion. First, the minerals in the meteorite were positioned in such a way that led scientists to believe that the source was not from Antarctica. Second, the age of the minerals within the meteorite were so old that they were definitely formed before the meteorite hit Earth.
There are many theories that deal with celestial objects delivering huge amounts of water to Earth. The “birth” of water on Earth was most likely started by either one or a myriad of large asteroids that crashed onto the planet. Of course, what this means is that we got rather lucky. The perfect placement of Earth in the Solar System combined with water-bring asteroids is what allowed life to prosper on Earth. As far as we know, there are no other planets that have had both these conditions met.
While the thought of our planet getting bombed by huge space rocks is not too pleasant, scientists suggest that this is most likely the reason for why we have life as it is. According to a report in Fox News, Hilary Downes, lead author and geochemist at the Birkbeck Institute of Earth and Planetary Sciences at the University of London, said that, “Although we rightly worry about the consequences of the impact of large asteroids, billions of years ago they may have brought the water to the Earth and helped it become the world teeming with life that we live in today.”
More studies are being done on the nature of the meteorite and its surroundings under the frigid Antarctic ice.