Astronomers studying how the Moon may have formed, have found proof that it was produced after a minor planet crashed into Earth about 4.5 billion years ago. And research proposes that this crash was so fierce that the 'planetary embryo' that hit Earth, called Theia, ultimately ended up fusing with both Earth and the Moon as a consequence. This particular theory that the Moon was formed as part of a Solar System crash isn't something new at all, but researchers in the past have suggested that Theia basically side-swiped Earth, slating the Moon into orbit and then continuing off into space.
For example, over 99.9 percent of Earth's oxygen is O-16, which signifies that each atom contains eight protons and eight neutrons. But there are also slight amounts of O-17 and O-18 on Earth. And it's the ratio amid O-16 and O-17 that researchers can use to figure out where rocks - and several other substances - have come from.
If Theia only side-swiped Earth and formed the Moon, the Moon would be made up mostly of Theia, and Earth and Moon rocks would have unlike oxygen isotope ratios. But what astronomers found something different.
Instead, the answers back up a theory suggested back in 2012, according to which Theia and Earth were really involved in a head-on crash, instead of a side-swipe, and eventually ended up fusing together as a result.
Our knowledge about Theia is not enough - Edward Young and his group consider that the planetary embryo was alike in size to Earth, although others believe it was nearer to Mars.
But Edward Young clarifies that there's proof that Theia was growing, and if it had lived after the crash, it would have turn out to be a planet in its own right.
If confirmed, the study which has been issued in Science, will modify our understanding of how our planet formed and developed.
It might also deliver some understanding about where our water came from - a head-on crash with Theia would have most likely exposed any water from Earth. If this is actual case, it may have only been carried back by small asteroid impacts tens of millions of years later.
Although it's pretty sad to think about our planet destroying another one in order to get where we actually are today, it's mesmerizing to ponder about all the accidents that had to happen to result in life on Earth.