Our moon was most likely the result of a violent collision between Earth and Theia, a long-hypothesized planet. Researchers at UCLA claim to have settled the debate, but aren’t quite sure about the intensity of the impact.
A new report emerging from UCLA strongly suggests the Earth’s moon was most likely formed due to a collision that took place 4.5 billion years ago between Earth and Theia. The second planet is believed to have been roughly the size of Mars. The violent impact is suggested to have created a mixture of debris that eventually coalesced into the grey round mass that revolves around the Earth.
— The Cosmic Calendar (@Cosmic_Calendar) September 2, 2015
Previous researches have suggested that the moon was made from an ancient collision between a planetary body and Earth. However, this study suggests the impact might have been much more violent than previously imagined. Earlier studies theorized that the raw material for the moon was formed after Theia merely grazed Earth, but the new study suggests it wasn’t a glance, but a full head-on collision. Incidentally, despite the research, there continues to be a strong debate, with researchers divided about the intensity of the collision.
Scientists have remained perplexed about the moon’s very existence and more importantly, it’s unusually close proximity to Earth. The moon is Earth’s closest celestial object and has been a very influential aspect in designing the Earth’s ecology. The moon has very low gravity, about one-sixth of that on Earth. Nonetheless, the moon’s gravity causes movements of the oceans, which is visible in the form of tides. Notwithstanding the movies, there is a firm belief among psychologists that moon has a significant impact on the brain and our moods. Many religions consider the moon sacred and calendars have been prepared that follow the moon’s visible pattern in the night sky. Despite the moon’s influence, the satellite’s actual formation has remained a mystery, till recent times.
— Discovery Space (@Discovery_Space) April 8, 2015
The study states collision between early Earth and Theia might have taken place about 100 million years after the birth of our solar system, reported NH Voice. Researchers theorize the impact was so violent, that materials from both bodies mixed completely before setting into the Earth-moon system. The secret they revealed lies in the rocks, which astronauts aboard the moon missions collected.
After comparing the seven lunar rocks collected by the Apollo 12, 15, and 17 missions, with six volcanic rocks that include material from Earth’s mantle, researchers concluded that the ratio of oxygen isotopes in lunar rocks was the same as that in the terrestrial rocks. They added that had the collision between Earth and Theia been just glancing blow, the oxygen isotope signatures of the rocks they studied would have been slightly different, reported the Hoops News.
The chemical composition of the rocks was closely examined using UCLA’s new mass spectrometer. It is a common assumption that rocks from different planets will contain different isotopes. The chemical identities hidden within the rocks can be considered as the planet’s fingerprints. However, as expected, the oxygen isotope signatures were remarkably similar, said Dr. Edward Young, professor at UCLA and lead of the study.
“We don’t see any difference between the Earth’s and the Moon’s oxygen isotopes; they’re indistinguishable. [The study] suggests that the moon-forming impact thoroughly mixed and homogenized the oxygen isotopes of Theia and proto-Earth.”
What’s even more interesting is that the researchers believe that the Earth’s water, too, could have been a gift by Theia. Much of our water may have been transferred by the planet, reported Techno Buffalo. Theia might have had huge reserves of water that lay trapped in minerals or as ice and was passed onto Earth during the collision.
[Photo by Karl Gehring / Getty Images]