<h1 class="pgc-h-arrow-right" data-track="1" will the Earth's interior be empty >? </h1>
In the background story of "Godzilla vs King Kong" and the same series of movies, these monsters are from the hollow earth, "Geocentric Adventures", there is also a hollow area with oceans and prehistoric animals and plants in the interior of the earth, the real world of the earth hollow theory was first proposed by the astronomer Harley in 1692, but with the development of geology in modern times and the continuous lifting of artificial satellites, the scientific community has not found the so-called "entrance to the geocentric world", and the hollow theory of the earth is gradually the same as the level theory. It has become a "performance art" that a few people are still insisting on.
Modern theories of planet formation and evolution essentially do not allow hollow planets to exist, because objects with a certain mass will collapse centripetally due to gravity, squeezing to fill the original cavity, making the planet a rocky metal planet like Earth, or a gas giant planet like Jupiter and Saturn, which is surrounded by gaseous material and has an ultra-high pressure solid core.
The cavity or cavity inside the celestial body may only exist in the irregular asteroid, any celestial body that exists independently in space, after its mass reaches a certain level, the original irregular appearance will automatically become spherical or approximately spherical due to static balance and gravitational influence, if the surface of the celestial body is wrapped in liquid water or gaseous material, the roundness of the planet will be higher.
So if we drain the Earth's oceans, the Earth is actually an irregular sphere with slightly flattened equator at both poles, and stars such as the Sun will change their shape irregularly because they are composed of dynamic plasma, but the degree of change is insignificant compared to the volume of the Sun, and the Sun is still so round.
In 2016, the International Journal of Geophysics published a paper about scientists detecting mass anomalies beneath the Pacific Ocean and Africa, which are structured much like the support columns of the original "hollow Earth", and the authors believe that these two mass anomalies in the mantle region did not exist at the beginning of the birth of the Earth, but originated from an ancient celestial collision.
<h1 class="pgc-h-arrow-right" data-track="1" > precisely, because of Theia</h1>
For hundreds of years, astronomers have been confused about the origin of the moon, nor can they explain how this planet with a diameter equivalent to a quarter of the earth appeared next to the earth, because jupiter, the most massive planet in the solar system, has a moon about the size of the moon, and the earth, as a planet with a mass equivalent to only one-318th of Jupiter, has a "giant natural satellite" similar to Jupiter's moon.
The current scientific community believes that the moon originated from the impact of a Mars-sized object with the early Earth 4.5 billion years ago, and astronomers named the object in this illusion "Theia", and the debris generated by its impact with the Earth was affected by gravity in the later orbit around the Earth, and slowly condensed into today's moon.
But not all of the debris became part of the moon, and scientists believe that during the violent impact 4.5 billion years ago, the core of Theia was actually "embedded" in the Earth's interior, and the fragments that finally reached the escape speed and made up the moon were only a small part of Theia and the ancient Earth.
By collecting vast amounts of seismic wave data, geologists have built a more elaborate model of the Earth's interior structure than ever before, and have discovered the mass anomalies we first proposed, beneath the Pacific ocean floor and below the African continent, which were formed by Theia's impact on the Earth.
At this stage, although the Theia impact theory is the most reasonable inference about the origin of the moon, the astronomical community currently has no definite evidence to verify this theory, and in the future, it can only launch a probe to cruise within the Earth-Moon system to see if it can find the fragments produced by the impact that have not yet been captured by the gravitational pull of the moon and the earth.
At present, although human beings can skillfully leave the earth, but the understanding of the earth itself and the earth's interior is actually not much, the former Soviet Union laid kola ultra-deep drill hole is only more than 10,000 meters deep, even the earth's crust has not been drilled through, the mantle and the core area can only be reversed by seismic waves, if you want to thoroughly understand the internal structure of the earth, the only way is to drill a deep hole as much as possible, and even directly drill through the earth like Liu Cixin's "Earth Cannon".