The Moon is believed to have been formed in massive impact when a planet the size of Mars collided with the primordial Earth. He is nicknamed Theia, after the Titaness and goddess of precious metals and jewels, and the mother of the Selene (the Moon) in Greek mythology. New research now reveals that Theia is not completely gone – there may still be large lumps of it inside our planet.
Around the heart of the Earth, scientists believe that there are two major structures called low-velocity districts (LLSVPs). One is under West Africa and the other under the Pacific Ocean. They are 1,000 kilometers (600 miles) thick and stretch for several thousand kilometers. Some researchers now believe that these blobs are lumps left by Theia.
“This clever idea is possible anyway,” Qian Yuan, a PhD student in geodynamics at Arizona State University told Science. Yuan presented his research at the 52nd Lunar and Planetary Science Conference last week.
The idea that these structures were pieces of Theia has been debated before, but this new work combines several pieces of evidence in a sensible position. Theia merged with the Earth, and their rights merged into one. Symbols run by the researchers show that Theia’s costume was a little denser than Earth’s own, and this allowed a large proportion of her fitness to survive. The range from the symbols suggests rocks 1.5 to 3.5 percent denser than those of Earth itself. Previous studies have suggested that LLSVP concentrations are within that range.
The simulation also suggests that Theia could be bigger than previously thought – perhaps as big as Earth. After all, the LLSVPs contain six times more mass than the entire Moon. So the influencer, if these structures are from the outside space, has to be quite large.
While the evidence presented paints a nice picture, many questions remain open regarding these structures that may influence this interpretation. The interior of our planet is examined using waves and seismic models, so errors may lie in it, creating a less detailed view. The LLSVPs may not be as thick or as thick or built in the way we believe. So there might not be a huge Theia behind those blobs.
The work has been submitted for peer review to Geophysical Research Letters and will certainly be discussed. The LLSVPs are a source of ongoing interest. They are even seen as a potential source of a major explosion in the future.