Riddle of the Moon points to erroneous conclusions about the origin of life on Earth
According to one of the most popular models of the Moon, the natural satellite of our planet could be the result of a collision of a celestial body with the earth more than 4, 5 billion years ago. This body was Theia, protoplanetary object to the "germ" of the Earth. The clash led to the ejection of matter Teyi and proto-Earth space, and because of this matter and the Moon formed, which explains its remarkable geological and chemical similarities with our planet. In the new study, scientists have tried to understand more what was the fate of our companion after the event.
During Katarchean (geological eon) Luna looked quite wrong, as it looks today. It represents rather lava lump having exotic superdense atmosphere of silicon vapor, and metals. And it was located 10 times closer to the Earth's surface than it is today.
In the study, a group of scientists came to the conclusion that one of the features of the moon may indicate that the Earth was stripped of the oceans of liquid water during the first 400-500 million years of its existence. But such a conclusion, in turn, impose serious constraints on the time of the origin of life on Earth. About his work, scientists have shared in the journal Geophysical Research Letters.
As it is now considered to be in the next few million years after its formation, Moon quickly removed from the earth as a result of tidal forces as a result did not come out on the orbit at which it is today. Subsequently, when the moon is beginning to look always to the Earth with only one hand, this process has slowed dramatically, and now it is moving away from a speed of about 2-4 centimeters of our planet in the year. Zhong and his colleagues have uncovered one unusual detail of this process, highlighting the most mysterious feature of the Moon - its unusual "hump", located on the equator. This structure was discovered by the French astronomer Pierre Laplace two centuries ago. Laplace noticed that the Moon is "flattened" at about 17-20 times stronger than should have been, given the speed of its rotation around its axis.
"Lunar equatorial" bulge "may contain the secrets of the early history of the evolution of the Earth, which we did not even know," - says the researcher Shijie Zhong of the University of Colorado at Boulder (USA).
The researchers believe that the existence of this structure indicates that in the distant past the Moon rotates much faster than today. The US planetary scientists have tried to figure out how fast the "brake" the moon, explore what's inside this "hump", and try to reproduce his appearance with the help of a computer model of the solar system.
These observations have surprisingly shown that the generally accepted theory of a rapid deceleration of the Moon in the early years of its existence were wrong - the rotational speed of the Earth's companion remained high for at least the first 400 million years of its existence. Otherwise, the moon would always remain "liquid" or the planet had a completely different shape and size than today.
Such a scenario, as explained by Jung, is only possible if the Earth was not at the time covered by ocean water, comparable in size to the current hydrosphere of the planet. This means that water in liquid form was not on the young Earth. It is either absent from it in principle or was brought after the formation of a "hump" of the moon, or was on it in a solid form, ie in the form of ice.
"The hydrosphere of the Earth, if it existed at the time, was completely frozen, causing the tidal forces are not almost" brake "the moon. The probable cause of this, we believe, may be the fact that the sun was shining while not as bright as it is today, "- says Zhong.
These findings raise serious restrictions on the time of the appearance of life on Earth and forced scientists to doubt the recent statements by geologists that the first living organisms could have originated on our planet for 4 billion years ago.