Lunar craters. What is it?Isn`t that so, naive question? Yes any school student, even initially focused on humanitarian type of thinking is able to answer it. However you do not hurry with categorical statements, and having armed with the field-glass, once again and more attentively peer into Selena`s face.
It is sure, every time you will find something new, interesting, mnogazhda seen earlier, but not noticed before the present. No, not about mountains and “seas“ the speech will go, though they deserve not smaller attention, and about craters, many thousands as if the pockmarks covering a face of our space fellow traveler.
Even Galilei did not believe the eyes when he by means of the telescope created by him saw the Moon which is repeatedly brought closer to the eyes when this space wanderer, many centuries being a symbol of mysticism, romanticism and love, suddenly turned in usual, as well as our Earth, space object. But not one more century was required to divide it between lyric poets and physicists, romantics and pragmatists, clerical dogmas were too strong.
So the great priest through a magic pipe saw? Yes, craters! Saw, assumed, but could not explain a phenomenon. For the time he was born too early. It was necessary to wait for the 20th century when the theory of meteorites, asteroids and volcanoes became axiomatic.
It is considered b that bulk of craters - an essence autographs of mnogomillionoletny activity of meteorites. Owing to lack of the atmosphere there by the definition the aeration mechanism does not work, there is no weather, but there are in the wide range differences of temperatures because of what the relief for billions of years is not exposed to a denudation. Here, unlike Earth, there are no sedimentary breeds.
Why all lunar meteoric craters have the correct concentric form, and with rather big diameter - disproportionately small depth and an equal bottom?
It would seem, funnel depth as from the blowing-up shell, it has to be equal to its diameter. But in that is continually that speeds of an artillery shell and a meteorite are far incommensurable that the speed of the last moreover acting at right angle, can exceed in tens of times that of a shell. Having met the Moon surface at such speed a meteorite, for thousand fractions of a second plunging into the spreading breeds on tens of meters, literally does not manage to blow up. All its huge kinetic energy, for the same scanty time passing in thermal, by the principle of a cumulative charge melts the containing breeds. Naturally, there is no Big Bang, but as a mud volcano there is an emission of the melted breeds what tells existence in these craters of piroksen, olivin about.
Why meteorites bombard a surface of the Moon or Earth at right angle, in a space these bodies can have absolutely other vector of the movement?
Just for the reason that for tens of thousands of kilometers from the purpose they get to a zone of gravitational influence of the planet. On the way to Earth a meteorite, spending all energy for overcoming of the atmosphere, just burns down. And if its size and speed allow to break this barrier, crashes into the Earth`s surface already with a speed of a usual artillery shell. The corresponding formya of depth also the funnel turns out.
Another, however, business on the Moon: at total absence of the atmosphere even at acceleration of 1,6 m/s it gathers the speed of tens km/s. Remember what speed and all at distance some there 30-35 km was gained in a free fall from a stratosphere by Felix Baumgartner: broke a sound barrier. There is no atmosphere, at the time of a contact its speed would already approach 2000 km/h. The funnel from it, of course, would not turn out, but a wet spot - precisely. And he jumped all from height of 39 km.
And one more question: why meteoric craters, plentifully covering continental part of the Moon, are practically absent at the bottom of “seas“ in water from the date of which creation of the satellite never existed? Most likely, these “seas“ were created much later and, being a product of volcanic activity, are metamorfichesko - magmatic educations in the form of basalts, granites, gneisses, syenites, diorites.
Theory of volcanoes. By analogy with terrestrial and regardless of activity degree all volcanoes due to periodic eruptions have to have carrying out cones (Klyuchevskaya Sopka, Tolbachek, Fujiyama, Etna, Vesuvius and so forth) And if in terrestrial conditions emissions at the expense of air streams dissipate on many hundreds of kilometers that considerably slows down process of formation of a cone, then in the conditions of the Moon and besides owing to lack of the atmosphere of such dispersion does not occur.
Why in that case and volcanic craters there flat? They do not pull and on mud, as the Icelandic geysers or the Hawaiian gayot because both the first, and for the second, require water availability.