A new study found that our Earth may have been formed by a massive impact with Theia.
The origins of the earth have always been a question. Researchers have long been looking back at our planet’s history in an attempt to find out more about both our planent and ourselves. Now, it appears Earth as we know it is actually two planets that smashed together, and the moon is a piece that broke off.
The Nasa-funded research team was lead by Edward Young, a professor of geochemistry and cosmochemistry at UCLA. According to the results of their study, somewhere around 4.5 billion years ago, when our planet was only 100 million years old, a “planetary embryo” called Theia hit it. While scientists have suspected the collision between Theia and Earth for many years, it was always thought to be more of a sideswipe. This new research, however, found it was likely a “violent, head-on collision.”
When Theia and Earth collided, Theia was supposedly about the size of Mars which, of course, would be a very large impact–big enough to knock a massive chunk off Earth and send it hurtling into space, where it would become the moon we see in the night sky today.
When researchers compared volcanic rocks from Hawaii and Arizona with moon rocks, they found them to be identical when it came to the oxygen isotopes. The rocks from all three places had shared chemical signatures. “We don’t see any difference between the Earth’s and the moon’s oxygen isotopes; they’re indistinguishable,” said Professor Young. “Theia was thoroughly mixed into both the Earth and the moon, and evenly dispersed between them. This explains why we don’t see a different signature of Theia in the moon versus the Earth.”
The study, published in the Journal of Science, also raises questions about our ocean. Researchers have toyed with the idea that the massive impact would have removed any water on Earth at the time, well before asteroids containing water hit millions of years later.
A few years ago, when the Rosetta spacecraft became the first to orbit a comet, it found some interesting data. Because Earth was so incredibly hot after it formed, it seems unlikely that there could have been any water on it. Researchers believe that in its infancy, Earth was a hot, desolate planet. Then, during an era called the Late Heavy Bombardment–an age when Earth was hammered by asteroids and comets for millions of years straight somewhere around 800 million years after the planet formed–water-laden comets and asteroids deposited much of our ocean’s water.
Something to think about when you’re surfing next time: the water you’re surfing on may have came from space, the planet you’re living on is made of two separate planets, and the moon you’re looking at was once attached to our planet. If that doesn’t make you feel small, then nothing will.
