“Truth does not change, because it is not considered to be by most people,” said the Italian Dominican monk, philosopher, mathematician, poet and cosmological theorist Giordano Bruno (1548-1600), who was ultimately tortured for his convictions. Of course, some lies are worse than others, and the lie that age is not considered a particularly sinister lie. Indeed, being in Earth orbit in 1971, the astronauts aboard Apollo 15 photographed a fascinating, annoying and confusing geological attribute — a strange, bumpy, D-shaped groove, about two miles long and a mile wide, that sirens sang. since then the song of the mysterious mystery. Some scientists have suggested that a strange feature called AT , testifies to the eruption of a volcano on Earth in the last 100 million years - approximately a billion years after it is believed that most of the volcanic activity on the moon has come to an end. However, new studies published by geologists in March 2017 show that AT can deceive scientists about their age and in fact not so young.
New research published in the journal geology , concludes that the strange feature really was formed by an eruption about 3.5 billion years ago, which makes it about the same age as the dark volcanic deposits that penetrate the near side of the moon. This is the very special form of lava that erupted from AT that help hide your real age, scientists believe the planet.
"I wonder how it would be for AT to form in the recent geological past, we simply do not think that this is the case. billions of years ago, ”explained Dr. Jim Hand on March 28, 2017, Brown University Press Release. Dr. Head co-wrote the article and is a professor at Brown University, University of Earth, Environment and Planetary Sciences in Providence, Rhode Island.
Footprints left in the moon dust
The moon of the Earth is the only body outside the Earth that we walked on, leaving our footprints in the lunar dust - the silent test that we once were. The moon-world satellite was with us almost from the very beginning, when our solar system was still being formed about 4.5 billion years ago.
As humans, we apparently need an understanding and explanation of our origin. The universal drama of natural phenomena cannot be explained solely as purely scientific - it is instead something universal. Thanks to the magical, fascinating myths and wonderful, beautiful stories in which superhuman heroes and heroines participate, as well as gods and goddesses, ancient prescientific civilizations tried to understand the mysterious, elusive complexes of the Cosmos. The Earth's moon has always represented humanity as a special hobby that inspired our human imagination for a long time to overcome some very frustrating limitations and — as we hunt for things that can exist outside of our earthly lives — help us move towards understanding who we are. in fact, in the Cosmic scheme of things, in all our confusing human complexity. The making of ancient gods and goddesses imitates our beautiful fish for human life that exists on our planet. In this particular context, there may be a lack of wisdom to completely embarrass the ancient wild myths — to put them aside, just as the fabrications of those who lived in an unsophisticated, long-forgotten and long-lost past.
There are over 100 satellites orbiting the eight major planets of our solar system. Most of them are icy, small worldlets which contain only relatively rare amounts of stony material — and most of these frozen small objects make them a fascinating dance around a quartet of gaseous giant planets inhabiting remote areas of the outer solar system — Jupiter, Saturn, Uranus and Neptune. In dramatic contrast, the warm and well-lit interior of our solar system - where our own Earth is - is nearly moonless. From a small, solid quarter to a tiny terrestrial planets - Mercury, Venus, our Earth and Mars - only Earth boasts the existence of a large and significant moon. Mercury and Venus are completely without a satellite of the Moon, and Mars is surrounded by an interesting, but small duet of lumpy, deformed moons duplicated Phobos and Deimos The two potato moons of Mars are often considered asteroids, which burst out of Main asteroid belt located between Mars and Jupiter, which were extremely captured by the gravitational arms of their adopted planet a long time ago.
The moon is a natural satellite in orbit around a larger body — for example, a planet that, in turn, rotates around a star. The moon is held in place both by the gravity of the object it is rotating and by its own gravity. On some planets there are moons; some not. Some dwarf planets - like Pluto - possess moons. Indeed, one of Pluto’s moon quintets, Charon, accounts for almost 50% of the size of Pluto itself, and some planetary scientists believe that Charon is actually a big piece of Pluto, which was broken in a monumental, catastrophic collision with another object, when our The solar system was much younger. In addition, some asteroids are surrounded by very small moons!
Volcanism on Earth
Huge plains of basaltic lava cover most of the lunar surface. Early astronomers, using primitive instruments, mistakenly believed that these plains were seas on the moon. Therefore, these dark areas were called mare (pronounced Mahra-ay) which is Latin for "sea". In addition, other other volcanic signs also appear in the lunar mare such as winding furrows , dark mantle deposits and small volcanic cones and domes. However, most of these volcanic features are somewhat small, and they constitute only a small percentage of the volcanic record left on the surface of the moon.
Volcanism on the Moon is different from volcanism on Earth. First, it is a matter of age. Volcanism on our planet is a continuous process, and many of earthly volcanoes are actually quite young on geological time scales — most often less than a few hundred thousand years. In dramatic contrast, most of the volcanism on the moon appears to have occurred from 3 to 4 billion years ago. mare Samples are typically around 3,500,000,000 years.
Even the youngest mare streams have an approximate age of nearly 1 billion years. These "young" rocks were not taken directly or dated. Therefore, the age of these breeds was not precisely determined. For comparison, the oldest rock on Earth was dated at about 3.9 billion years. The most ancient basalts of the seabed on our planet are “simply” 200 million years — a brief period in geological time scales. Since the Moon does not detect signs of recent volcanic or geological activity, it is sometimes called a “dead” object.
Location mare volcanism shows another significant difference from volcanism, which occurs on our planet. Terrestrial volcanoes are mainly found in long linear mountain ranges, such as the Andes, which mark the edge of the lithospheric plate. Mountain ranges, such as the Hawaiian Islands, trace past plate movements above a hot spot on the Earth’s mantle.
But moon mare usually occurs at the bottom of ancient, large impact craters. Therefore, most mare have an almost round shape. In addition, the lunar mountain ranges form the edges of these shock basins and tend to surround the lunar mare. There is also no evidence that plate tectonics ever occurred on the moon.
Lunar mare most often found only on one side of the moon, covering almost one third of the lunar near side, but only 2% of the far side. However, the lunar surface is much higher on the opposite side, and the crust is usually much thicker. Therefore, the most important factors controlling volcanism on the moon are the height of the surface and the thickness of the earth's crust.
There are some significant physical differences between volcanism on our planet and its lunar satellite. First, lunar gravity is only one sixth of the Earth. This forces the forces that drive the flows of lava, much weaker on the moon than on earth. Flat smooth mare the surfaces suggest that the lavas that formed them were rather liquid. They can easily flow and spread over large areas of the lunar surface. In addition, relatively weak gravity could cause explosive eruptions that could throw debris on the moon further than on Earth. Therefore, the eruptions on the moon should smear the lava in a wide flat layer, in contrast to the cone-shaped objects on our planet. Secondly, the dry moon of the Earth has practically no dissolved water. In fact, the so-called "seas" are dry, like bone. In dramatic contrast, water is one of the star players in Earth’s lavas. Water is also important for driving strong volcanic eruptions on Earth. Therefore, the lack of water on the moon should significantly affect lunar volcanism. This is due to the fact that without water, explosive and violent volcanic eruptions are much less likely on Earth than on Earth. Indeed, the lunar lava must flow quietly, smoothly and even gently on the surface of the moon.
AT: Dead Moon Volcano
AT located near the top of a gentle hill of basaltic rock. This place led many planetary scientists to suggest that it was probably the caldera of an ancient volcano on the moon. However, it was difficult to determine how ancient AT actually. While the flank of the volcano seems to be billions of years old, AT The caldera itself looks much younger. One misleading feature Ina & # 39; s The so-called "youth" is its bright appearance in relation to the environment. Brightness indicates that AT has tender years and does not have time to accumulate a large regolith. regolith is a layer of loose rock and dust, which over time accumulates on the surface.
In addition, there are about 80 individual mounds found on AT. These mounds are smooth hills composed of rocks, and some reach a height of 100 feet, dominating the landscape of the caldera. Mounds show a much smaller number of impact craters compared with the surrounding area - another sign of relative youth. Older surfaces are damaged by more craters than younger surfaces. This is due to the fact that over time it is expected that the surface will accumulate more and more craters as a result of the impact of objects. Craters must be of different sizes and accumulate at fairly constant speeds. Knowing this, planetary scientists use the number and size of craters to calculate the relative age of a given surface. In 2014, a team of planetary scientists conducted a very cautious crater account. Ina & # 39; s and came to the conclusion that they must have been formed by lava, which came to the surface in the last 50-100 million years, which indicates youth.
“It was a really puzzling discovery. I think most people agree that the volcano AT was created billions of years ago, which means that during volcanic activity for more than a billion years or more there was a pause as a result of activities that formed AT. We wanted to find out if there could be something inside the geological structure. AT which discards our estimate of his age, ”explained Dr. Chapter in March 28, 2017. Brown University Press Release.
To solve the mystery Ina & # 39; s true age, a team of scientists looked at the well-studied volcanoes on Earth, similar to AT. AT is a crater pit on the shield of a volcano, a gentle mountain, which is comparable to Kilauea Volcano in Hawaii. Kilauea displays a crater pit similar AT which was named Crater Kilauea Iki which began in 1959.
Lava, which was knocked out of this eruption, hardened. As it was done, it formed a very porous layer of rock inside the pit, with subsurface vesicles reaching three feet in diameter, as well as a surface void space at a depth of two feet. Dr. Head and his colleagues suggest that the porous surface is formed by the type of lava that broke out in the later stages of events, such as this particular eruption. As the subsurface lava feedstock began to decrease, it ejected what was called "Igneous foam" which is a frothy combination of lava and gas. When it cools, igneous foam turns into a solid, and at the same time it creates a highly porous surface.
Dr. Head and his team suggest AT the eruption will also be made igneous foam In addition, due to the comparatively weak gravitational capture of the moon and the almost non-existent atmosphere, the lunar igneous foam would be fuzzy than on earth. As a result, scientists suspect that structures hidden inside AT even more porous than on earth.
This is the high porosity of those surfaces that present problems with date estimates for AT , both by smoothing the accumulation of the regolith and dropping craters.
A very porous surface, according to Dr. Head and his collections, would cause dust and loose stone to invade empty space. It would do it. to appear as if less regolith had been accumulated. This process will be strengthened by the seismic pushing in the area, much of which is the result of continuing meteor impacts. "It's like knocking on the side of a sieve to make flour." Regolith is pushed into holes, and does not sit on the surface, making AT look much younger, ”explained Dr. Hain March 28, 2017 Brown University Press Release.
This high porosity also affects the number of craters. Laboratory experiments using high-speed cannon guns have demonstrated that impacting porous targets creates much smaller craters. because of Ina & # 39; s scientists believe that their craters are much smaller than usual. Therefore, many of the craters may not be visible at all. This would drastically change the age estimate obtained from crater counting.
Then a group of planetary scientists estimated that this highly porous surface would be reduced by three times the size of the craters mountain ash. Ina & # 39; s mounds. This is due to a drummer who would excavate a crater with a diameter of 100 feet in the fundamental foundation of the lunar basalt, would form a crater just over 30 feet in magmatic powder. Taking this crater reduction into account, planetary scientists came to a revised age for AT about 3.5 billion years old. This age is similar to the surface age of the volcanic shield that surrounds AT - and also AT activities within the framework of calculated volcanism on the moon.
Planetary scientists believe this study provides a plausible explanation. Ina & # 39; s without having to resort to the mysterious milliard lack of volcanic activity.
The lead author of the study is Le Qiao, a medical student visiting Brown University from China University of Geosciences.
Dr. Head said March 28, 2017 Brown University Press Release that "we believe that young AT are a natural consequence igneous foam eruptions on the moon. "
