Volatiles and water are almost absent from the moon's surface, as they evaporated in a giant collision. This conclusion was reached by American and French scientists after analyzing rocks from the area where the world's first nuclear bomb was tested. The researchers' work is published in the journal Science Advances.
One of the theories of the origin of the Moon suggests that it appeared as a result of a catastrophic collision of the young Earth and Theia. A protoplanet the size of Mars slammed into the Earth at an angle, and most of the impacted object, as well as some of the material in the earth's mantle, were thrown into near-Earth orbit. From these "debris" the Moon was formed and began to revolve around our planet.
This hypothesis explains well why very few volatile substances are observed on the Moon, in contrast to its neighbor, the Earth. According to the researchers, they could simply evaporate due to the extremely high temperatures and pressures. However, this assumption is difficult to verify, since scientists in the laboratory cannot reproduce the temperature or even the remote scale of such a process. However, events have taken place on Earth that can serve as a model for planetary research: one of them is the Trinity nuclear bomb test conducted in 1945 in the state of New Mexico, USA.
During the explosion, which was equivalent to approximately 21 kilotons of TNT, the sand on the nearby surface melted into a thin layer of glass, or trinitite. He was exposed to temperatures over 8 thousand degrees Celsius and a pressure of about 80 thousand atmospheres. According to scientists, these conditions are close to those that arose during the formation of the moon.
The authors studied the distribution of one volatile element, zinc, as well as its isotopes in trinitite samples. The researchers noticed that the closer to the epicenter of the explosion was trinitite, the less it contained zinc and its light isotopes. This is because they evaporated in the process. At the same time, heavier zinc isotopes (66Zn) showed an inverse relationship - their concentration increased as they approached the point where the tests took place.
Since studies of lunar rock samples show that the lunar soil also contains few volatile elements and compounds, including light zinc isotopes, the authors of the work believe that their study testifies either in favor of a great collision in ancient times, or in favor of the existence of a magma ocean. that arose after him. As a result of these events, volatile elements and compounds could simply evaporate.
Christina Ulasovich