Giant Impactor Theory Vs Capture Theory

The two theories being compared are The Giant Impactor Theory and The Capture Theory. The Giant Impactor Theory states that about 4.5 billion years ago a mars-sized planet called Theia collided with the proto Earth generating enormous amounts of debris from Earth’s outer layer. These “hot degassed material[s]” started to join together and form our Moon(Wilton, paragraph 11). The Capture Theory states that a rocky body formed somewhere else in the universe and was captured by Earth’s gravity and set into orbit around it. These are just two theories for the Moon’s origin, but every theory has the base problem of explaining the moon’s low density, the nearly identical oxygen isotopes that it shares with Earth, and the few volatile substances.

“The early solar system was a violent place, and a number of bodies were created … one of these bodies [Theia] crashed into Earth not long after the planet was created.” (Redd, Paragraph 2). According to Newton’s third law, for every action there is an equal and opposite reaction, the action of Theia crashing into Earth had a reaction of throwing vaporized parts of Earth into space. Then, with the help of gravity these particles fused together to create the moon. The Moon having particles from Earth helps to explains why isotopic compositions of oxygen and titanium are present on the Moon ,and therefore Earth, but very sparse in every other rocky body in our solar system. All of this information is why The Giant Impactor Theory is the most accepted theory, in the science community, of how the moon came to

The Giant Impactor Theory can show evidence of the low density of the moon because when Theia hit Earth it vaporized the top crust of Earth that is much less dense than the inner iron-core. It also can explain why the Moon and Earth share the same rare isotopic compounds of oxygen and titanium. It partially explains why the Moon lacks volatile substance from lunar baking because it had around the same years of exposure to the Sun as Earth did , but it had a much less protective atmosphere around it. The capture theory can explain why the Earth and Moon have different chemical compositions, but it lacks why they share certain isotopic substances. This theory also is very unknown on the lack of volatile substances because we don’t know if it had lunar baking while traveling through the solar system. Based on this information, The Giant Impactor Theory better explains the Moon’s unique