What the science of today knows about the caves, located nanih planets? Because caves from ancient times are interested in people, their darkness, full of danger, though afraid, but at the same time attracts. Her deep secrets lure virtually any person, whether ancient man, modern scholar, or an ordinary tourist. In this article we will talk about all kinds of caves, particularly on the moon and Mars, and how at the moment the possibility of their study. Is it simple? Can scientists at the moment to implement technology to explore these caves? More on that later.
On Earth scientists have known hundreds of terrestrial and underwater caves, however, ahead of they see a more complex goal – caves located on other planets. Vitaly Egorov («the Green cat»), is a blogger and populariser of science about the cosmos, revealed that the same should be expected for future space explorers.
Much of the known terrestrial caves have been formed by erosion processes, namely, the destruction of rock by water and dissolved chemical compounds. Such caves are called karst. In the regions where there are volcanoes, notably common cavity under the ground, which result from the actions of lava. Among them are the domes and tubes. Volcanic caves are remarkable in contrast to the karst that they are formed very quickly, at the time of eruption and active lava effusion. Karst is formed over thousands and millions of years.
A lava tube is called the extended tunnel of natural origin. Its length sometimes reaches several tens of kilometers. it has flat floor and arched ceiling. The tube is formed during the eruption of liquid and viscous basaltic lava. Lava flow spreads from the source and gradually cools down. First harden the top crust under which lava continues to flow. Because of the gases in the volcano between «roof» and a lava flow is a kind of cavity, expanding the depletion of the stream. In the end it turns out the real «underground», which is suitable for foot travel. Due to the high gas pressure summary pipe secondary melt, so sometimes it is covered with lava stalactites.
Volcanoes can also operate on other planets
Several indirect signs indicate the possibility that on Venus’s volcanoes are still erupting. Due to the heat that there is, the lava freezes much slower, consequently, streams become wider. It has been suggested that sulphur compounds contribute to the fact that the melting point of lava on this planet is lower than Earth. This lava flows are active.
We know that on Mars there are volcanoes of gigantic proportions. However, now they’re all asleep, but before his «sleep,» they’ve already managed to fill a few thousand square kilometers of the territories of basaltic lava.
The moon somehow also managed to survive a very active period. He is due in particular to the asteroid bombardment and the internal activity of tectonic plates. The moon flooded the vast lava flows which we call seas.
That the moon and planets of our system must be a lava cave, researchers suggest began in the 19th century, but the first opening occurred only with the advent of space exploration.
Caves Of Mars
Back in the 1970s, the automatic interplanetary station was discovered collapsed volcanic tube, located on the slopes of volcanoes. Martian’s.
After 30 years of Sputnik «Mars Odyssey» said the first failures, pointing out some of the caves, who waited for the cavers. The diameter of the failures reached 250 m. the largest number was found on the slopes of shield volcanoes, situated in the highlands of Tharsis. Modern apparatus «Mars Reconnaissance Orbiter» through the telescope with high resolution «HIRISE» looked into the depths of Mars, as it was possible from orbit.
Caves of Mars attractive to scientists due to several features. For example, the thin atmosphere allows the whole surface to be irradiated with ultraviolet light from the Sun and bombardirovschika space charged particles, so that in the upper soil layers hardly can exist the germs, or the more complex organic compounds. Thanks to the protection of the cave vaults, the chances of the safety of such a sharp image becomes higher. That is, even in the absence of life there, the remains may lie there much longer. Still it is possible that such caves will find water ice and other more volatile compounds.
The most daring dreamy people voiced the suggestion that the cave may serve as a shelter for the first human bases and settlements. They are very effective in protecting against radiation. However, there are factors, saying that these volcanic caves are not a suitable place for life. For example, all these objects are located on the slopes of volcanoes at a height of several km above the plain. However, land in mountainous areas is very difficult to implement because of the too thin atmospheric layer. The atmosphere allows you to save fuel by braking at the time of landing, so the most difficult devices for space applications tend to drop in the deepest places on the planet. This atmosphere also helps to protect the lowlands against radiation. On the surface even managed to study deposits of water ice. Water ice is studied, in particular, in the valley of Hellas, is the deepest basin on Mars. So now have not confirmed the fact of presence in the caves of Mars biogenic or other resources. The study they are more appropriately carried out by robotic means.
An important factor hindering the development of Speleology on Mars, are security requirements on the planet. In the presence of probability of preserving the potential of life on Mars in the caves of the researcher should be 100% sterile to eliminate the possibility of a scenario of fiction «the Martian Chronicles», where due to only one person’s sneeze had ruined a great civilization. Currently, ensuring complete sterility of the device on the Ground is impossible, and microbes of the earth may be as carriers of the conditions of space flight. So the search for Martians is not possible, so you do not accidentally destroy them.
It should be noted that the doctrine of the security of the planet is not a hindrance, fortunately, the visit to the caves on the moon. The full Moon has been at the epicenter of the attacks in works of fiction. With all that the reality is very far from fantasy, still it gives hope to romantics. In old times there were assumptions that on the moon there are caves. However, until 2009 no direct evidence to support these statements was not provided. Only in 2009 by the automatic station of Japan «Kaguya» was first spotted an unusual kind of craters that did not have a circular shaft and any emission from within. Diameter they went up to 100 m Depth at them so huge that the side light of the Sun simply couldn’t reach the bottom. American probe «Lunar Reconnaissance Orbiter» considered failures in detail, and exactly what are they in a different time of day. Also, the device is allowed to evaluate not only the bottom depth and just what it contains, but also the structure of the side wall. Another machine gave the opportunity to look at the vaults.
A group of scientists from the University of Arizona, was developed a special algorithm for «PitScan», to seek in semi-automatic mode the cave dips on the lunar surface and found them more than 200. Those are divided into 3 relative categories:
· Failures of channels through which the lava during the eruption of the volcano.
· The lava cavities formed by the melt that originated in the craters of large sizes due to the fall of a large asteroid.
· Cavity in the lunar seas.
The potential breach in a lava tube was visible on the volcanic plateau, the Marius Hills, located near the equator in the West of the visible side of the moon. With satellites it is clearly possible to see the flow of lava, stretching from the volcanic vents on the a dozen miles away Approximately 25 km from the crater in a frozen stream visible hole. It could be a meteorite, but could be that the so-called «roof» fell by herself, but now we see an opening, whose width reaches 80 m and the depth is 45 m. the width of the flux in the region of the holes reached 800 m, and upstream up to 1 km, so there is apparently a giant sized tunnel.
At Purdue University numerical simulation was carried out, whereby the strength characteristics of basalt lava, and the low gravitational force on the moon give the ability to save without destruction of the arches of tunnels, the width of which reaches 1 km at the surface, as well as rooms with a width of up to 5 km at a depth of several hundred m.
In comparing the simulation with reality helped information about the gravitational field of the moon, obtained with probes of the «GRAIL». Scientists took into account the evidence of the «GRAIL» over a possible cavity in the Marius Hills and tried to find the same data elsewhere. Thus, they managed to find up to a dozen «signatures» of possible cavities of the moon, some of which the length is 100 km and width of several km. Larger number of those not found under the seas of the moon.
A number of holes in the seas of the moon was actually found, but they are not consistent with those voids, calculated from the deviations of the gravitational field. But still one hole in the Sea of Tranquility approximately 400 km to the North-East side from the landing site «Apollo 11» is the largest and deepest of the viewed from the satellite. The hole diameter reaches about 100 m as the depth. Near not seen any lava channels and volcanic domes, is able to indicate the presence of the tunnel, but such presence it was possible to do anyway.
The hole scientists are interested not only the ability to hide on the bottom, but the presence of a special layered structure, prominent on the steep walls of failure. These layers give scientists a clue about what the lava sea is formed due to multiple lava spills, some of which were very thin, and it reached only the 1st m
Hole in the Sea of tranquility is still one of the most suitable places for landing of a robotic camera probe and to explore the innards of the cave. But now still no Agency puts in plans to create a lunar robot explorers. The plan of the mysteries of lunar lava tubes has progressed, the astronauts «Apollo 15», engaged in the research of the slopes of the canyon Hadley Rill, the former, according to one of the assumptions, once a lava tube, but then were completely destroyed.
Future interplanetary spelunking
On Earth while preparing for future studies of caves on Mars and the moon. On Earth to explore and visit, you may notice quite a lot of volcanic caves, allowing to present all the difficulties and problems of interplanetary spelunking. In Russia, lava tubes and caves occur in Kamchatka. One of the lava tubes at length comes to approximately 100 m. It is available in the Caldera of Gorely volcano. This cave is very old. She was left by a volcanic eruption that occurred about 2 million years ago. It is possible to feel like a Mars probe due to the close to zero temperature indicators, as well as a huge glacier, partially covering the entrance.
A number of caves was formed during the eruption of the volcano Tobechik that occurred in 2012-13 these caves are seen more picturesque. They are remarkable lava stalactites that cover the ceiling, salt efflorescence on the ceiling, as well as the younger stalagmites are on the floor. There is also the heat of the cooling lava liquid. Hot cracking still there is a possibility of boiling tea, and some cave branch is not available now to visit due to the high temperatures.
Despite the obvious scientific interest in cave exploration of other planets, still none of the agencies didn’t step towards learning their secrets. A major obstacle here is the lack of sufficient technical implementation of the research in this regard. If you apply the probe, it will be necessary to either put exactly on the bottom of failure, or to equip the climbing equipment intended for the descent on a vertical wall. One such step is not enough to stop the entire development, because very high complexity and large risks. You will then need power supply of a robot at the cave of darkness, and it is important to think about managing and maintaining communication without direct radio line of sight.
In the research work of the cosmic plan all the time, preference is given to projects guaranteeing high reliability and long-term supply of unique information, so that the robotic explorers are in this respect in a losing position in comparison with satellites and telescopes. Only a few private teams participating in the competition, called «Google Lunar XPRIZE», made an announcement about their development, giving the opportunity to explore caves on the moon. Team «Astrobotic» from USA and «Long» from Japan see the caves on the moon as their goals, but at this point the probes are still on Earth and on the moon they will need to pass 500 meters for the victory. Here is the problem: the lunar caves – a very rare occurrence, there is also the complexity of exact fit, so it is unlikely the team the first time will reach the lunar cavities.
In this article, we walked through very deep themes such as caves on the moon, caves on Mars, volcanoes on other planets, and the prospects of technology development in order to explore the various caves at least very near to us space objects such as Mars and the Moon. We found that, unfortunately, the implementation of the so-called interplanetary spelunking at the moment is only at the level of ideas, ideas, but in practice it is very difficult. However, as we above said, some companies are already focused on the study of caves on the moon. Remains to be of new discoveries and steps towards implementation of these ideas and plans. So the cave despite the extensive knowledge about them, yet are mysterious objects, unidentified until the end, so everything is still ahead.