temperature on Mars. Planets of the solar system. Dust storms on Mars: truth and fiction - Sur Bere Are there storms on Mars

For more than a century now, science fiction writers from all over the world have been trying to imagine what life would be like for astronauts on Mars. But as humanity becomes more and more more and more knowledgeable about Martian conditions, a description of life on Mars science fiction are becoming more realistic. More recently, The Martian is based on Andy Weir's sci-fi novel. The protagonist"Martian" due to unforeseen circumstances remains alone on the red planet and begins the struggle for survival. And at the beginning of the 20th century, the American author Edgar Rice Burroughs was already dreaming of traveling to Mars. In fairness, it’s worth saying that the red planet captured people so much that even the famous theologian and author of fantasy stories, Clive Staples Lewis, published a series of stories about it. It was he who created the cycle "The Chronicles of Narnia".

An artist's impression of a dust storm on Mars approaching a research station. Such phenomena on the red planet may well be accompanied by discharges of atmospheric electricity. Source: NASA

The Martian opens with a huge sandstorm that damages the transmitting antenna and some of the equipment, causing the fictional character Mark Watney to remain on Mars while the other mission members leave, presuming he is dead. This development looks very plausible, since Mars is known for its very active sandstorms, which sometimes become so large that they can be observed in telescopes on Earth.

“Each year, moderately large sandstorms occur on Mars, which cover areas the size of the Earth's continent and last for weeks after their formation. But about every three Martian years (5.5 Earth years), ordinary hurricanes turn into giant storms that can envelop the entire planet, ”- Michael Smith, planetary scientist from the Center space flights NASA.

Scientists consider it unlikely that even planetary sandstorms on Mars will be able to lead to dire consequences. Even the strongest winds that are blowing at this time will not be able to destroy or even topple the specially deployed mechanical equipment. The winds in the strongest Martian hurricanes reach speeds of about one hundred kilometers per hour, more than half the speed of some hurricanes on Earth. That is why it is not worth focusing only on wind speed. Atmospheric density Mars makes up about one percent platmosphere Earth. This means that in order to fly a terrestrial kite on the red planet, the wind must blow much stronger.

“The main difference between Earth and Mars is that Atmosphere pressure much less on Mars. Thus, things and objects can be carried away from its surface, but not with the same force as on Earth,” William Farrell, plasma physicist.

Problems of solar energy

But be that as it may, the sandstorms of Mars are not completely harmless. Individual dust particles on the red planet are very small and slightly electrostatic, thus being able to "stick" to various surfaces.

“If you've ever paid attention, you can see in the pictures of the Curiosity rover that after each trip it gets very dirty. Dust covers almost everything. It even penetrates mechanisms and devices, ”- Michael Smite.

This ability of dust to penetrate anywhere and everywhere is a major problem for engineers designing equipment for Martian rovers. This is especially a big problem for solar panels. Even if the craft is caught in a very small dust storm or swirl, only a few meters in size, the wind can carry enough dust to cover the photovoltaic converters and greatly reduce the usable surface that can convert solar energy into electrical. If we turn to the same "Martian", then Mark Watney spends a certain amount of time every day to clean the solar panels to ensure their maximum performance.

This picture of itself was taken by the Opportunity rover three weeks before its 10th anniversary on Mars. The Pancam panoramic camera surveyed the rover between January 3rd and 6th, 2014. Pay attention to how dusty the solar panels are. Source: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.

Global hurricanes can also create a secondary problem that cannot be solved by simply blowing dust off the surface. So much dust can be permanently present in the atmosphere that some part of the sunlight will be blocked, and, consequently, the efficiency of solar panels will decrease. In the book, when an astronaut first encounters a large sandstorm, he immediately notices a slight decrease in the efficiency of his batteries, caused by a slight dimming of the atmosphere. It's pretty exact description what researchers may encounter during real Martian expeditions.

“Currently, we are very concerned about the power consumption of our rovers. The Spirit and Opportunity rovers landed in 2004, so they've only survived one global hurricane so far in 2007, which forced them to shut down and go on standby for a few weeks,” continues Michael Smeet.

dust bustle

As mentioned, global sandstorms kick up enough dust into the air to completely cover the planet and obscure the sun. but in this way the hurricane itself also becomes doomed to extinction. The fact is that the main mechanism that sets in motion all these hurricanes is the high temperature of sunlight, which reaches exactly the surface of the planet. As the light hits the ground, it heats up the air close to its surface, leaving the upper layers cooler. As well as on Earth during thunderstorms, warm and cold air, mixing, become unstable, warm layers begin to rise, taking away dust particles with them due to instability. It is from such small swirls that all those strange dust “ghosts” seen in some images of Mars are formed. Then moderate-sized storms form, then - the size of a continent. Sometimes such large hurricanes can combine into one global vortex, which just covers the entire planet with dust.

Researchers and planetary scientists have determined quite accurately that large hurricanes usually occur during the summer in southern hemisphere Mars. It is known that on the red planet, as well as on Earth, there is a change of seasons, which is caused by the tilt of the planet's axis of rotation. But due to the fact that the orbit of Mars has a greater eccentricity than the orbit of the Earth, the red planet moves along more elliptical orbit. The minimum approach to the Sun just coincides with summer period in the southern hemisphere, and, consequently, the temperature values \u200b\u200bare greatest just then. Once a hurricane begins, it does not subside for weeks and even months. But scientists are still unsure what exactly causes such large gaps between hurricanes.

Dust whirlwind captured on Mars by the HiRISE camera orbital station Mars Reconnaissance Orbiter. This scene was captured during daytime in late Martian spring. The frame covers an area measuring 644 meters. Judging by the shadow that the vortex casts on the surface, it was possible to establish that it can reach 800 meters in height, and its diameter is about 30 meters.

NASA has told truth and fiction about the dangers of dust storms on Mars, some of which may be visible from ground-based telescopes. This information was used in the creation of the new film "The Martian" directed by Ridley Scott. This was reported on the NASA website.

The Martian, which will be released in October 2015, begins with Andy Weir's character (astronaut Mark Whitney) facing a massive dust storm. She rips off the transmitting antenna and destroys part of the camp. NASA does not deny that dust storms are one of the troublesome features of the Red Planet.

"Mars experiences moderate-to-large dust storms every year that cover areas the size of an Earth continent and last for weeks," said planetary scientist Michael Smith of NASA's Goddard Space Flight Center in Greenbelt, Maryland.

Meanwhile, on the Red Planet, as the scientist noted, much stronger storms are also observed. Global dust storms form from moderately large ones and manifest themselves on average once every three Martian years (this corresponds to about 5.5 Earth years).

However, as the scientist notes, it is unlikely that these dust storms can even disturb the hair of an astronaut on the Red Planet (if the latter decides to take off his spacesuit). In addition, even global dust storms are unlikely to be able to topple or destroy any equipment.

This is due to the fact that the speed of the strongest winds on Mars does not exceed 27 meters per second, which is more than twice as low as the speed of some hurricane winds on Earth. In addition, the density martian atmosphere a hundred times smaller than the earth.

“The main difference between Earth and Mars is that the atmospheric pressure on the Red Planet is much lower,” said plasma physicist William Farrell. “Thus, all particles in the atmosphere of Mars become wind, but not with the same intensity [according to compared to the Earth].

However, dust storms on Mars are not entirely harmless. Individual small dust particles can carry an electrostatic charge and "stick" to surfaces, in particular portholes and mechanical parts of scientific equipment.

The neutralization of electrostatic charges and the elimination of dust pollution is one of the main tasks that engineers solve when designing equipment for Mars exploration.

This dust is a big problem for solar panels. Even small dust storms can bring enough particles onto solar panels to significantly reduce the amount of solar energy.

In the movie The Martian, astronaut Whitney cleans up dust pollution from solar panels every day. NASA also notes that global storms on Mars may also lead to some dimming of the Red Planet's atmosphere.

“We were really worried about the energy of the rovers. The Spirit and Opportunity rovers that landed on Mars in 2004 only experienced a global storm once (in 2007) and went into survival mode for a few weeks,” Smith said.

Most often, global dust storms on Mars occur in the summer in the southern hemisphere of the planet. As on Earth, the seasons on the Red Planet are determined by its inclination to the plane of the orbit. However, the orbit of Mars is more elongated compared to the Earth, which means that during the Martian year one side of the planet is heated more than the other.

Meanwhile, scientists do not yet know the true cause of the long intervals between storms. They have been observed since 1909, when a global storm was first observed on the Red Planet. Last time This a natural phenomenon was noticed in 2007. Scientists hope to observe it again soon.

The planet Mars, like another close neighbor of the Earth, Venus, has been subjected to the closest study of astronomers since antiquity. Visible to the naked eye, since ancient times it has been shrouded in mystery, legends and conjectures. And today we know far from everything about the Red Planet, however, many of the information obtained over centuries of observation and study dispelled some myths and helped a person understand many of the processes taking place on this cosmic object. The temperature on Mars, the composition of its atmosphere, the features of orbital movement after the improvement of technical methods of research and the beginning space age managed to move from the category of assumptions to the rank of indisputable facts. Nevertheless, much of the data about both such a close and such a distant neighbor has yet to be explained.

Fourth

Mars is located one and a half times farther from the Sun than our planet (the distance is estimated at 228 million km). According to this parameter, he takes the fourth place. Beyond the orbit of the Red Planet lies the main asteroid belt and the "possession" of Jupiter. It flies around our star in about 687 days. At the same time, the orbit of Mars is strongly elongated: its perihelion is located at a distance of 206.7, and aphelion - 249.2 million km. A day lasts here only almost 40 minutes longer than on Earth: 24 hours and 37 minutes.

little brother

Mars belongs to the planets terrestrial group. The main substances that make up its structure are metals and silicon. Among similar objects in its dimensions, it is only ahead of Mercury. The diameter of the Red Planet is 6786 kilometers, which is about half that of the Earth. However, in terms of mass, Mars is 10 times inferior to our space home. The area of the entire surface of the planet slightly exceeds the area of the earth's continents combined, without taking into account the expanses of the oceans. The density here is also lower - it is only 3.93 kg / m 3.

The search for life

Despite the obvious difference between Mars and Earth, for a long time it was considered a real candidate for the title of a habitable planet. Before the beginning of the space age, scientists who observed the reddish surface of this cosmic body through a telescope periodically found signs of life, which soon, however, found a more prosaic explanation.

Over time, the conditions under which even the simplest organisms could appear outside the Earth were clearly defined. These include certain temperature parameters and the presence of water. Many explorations of the Red Planet have been aimed at discovering whether a suitable climate has developed there, and, if possible, to find traces of life.

Temperature on Mars

The Red Planet is an inhospitable world. Considerable distance from the Sun significantly affects climatic conditions this cosmic body. The temperature on Mars in Celsius varies on average from -155º to +20º. It is much colder here than on Earth, since the Sun, located one and a half times further away, warms the surface half as weakly. These not the most favorable conditions are exacerbated by a rarefied atmosphere, which transmits radiation well, which is known to be detrimental to all living things.

Such facts reduce to a minimum the chances of finding traces of existing or once extinct organisms on Mars. However, the point in this issue has not yet been set.

Determining Factors

The temperature on Mars, like on Earth, depends on the position of the planet relative to the star. Its maximum indicator (20-33º) is observed during the day near the equator. Minimum values (up to -155º) are reached in the vicinity of South Pole. Significant temperature fluctuations are characteristic of the entire territory of the planet.

These differences affect both the climatic features of Mars and its appearance. The main detail of its surface, noticeable even from the Earth, is the polar caps. As a result of significant heating in summer and cooling in winter, they undergo tangible changes: either they decrease until they almost completely disappear, then they increase again.

Is there water on Mars?

When summer comes in one of the hemispheres, the corresponding polar cap begins to decrease in size. Due to the orientation of the planet's axis, as it approaches the perihelion point, the southern half turns towards the Sun. As a result, the summer here is somewhat hotter, and the polar cap disappears almost completely. In the north, this effect is not observed.

Changes in the size of the polar caps led scientists to the idea that they are composed of not quite ordinary ice. The data collected to date allow us to assume that a significant role in their formation is played by carbon dioxide, which in in large numbers contains the atmosphere of Mars. In the cold season, the temperature here reaches a point at which it usually turns into the so-called dry ice. It is he who begins to melt with the advent of summer. Water, according to scientists, is also present on the planet and makes up that part of the polar caps that remains unchanged even with an increase in temperature (heating is not enough for it to disappear).

At the same time, the planet Mars cannot boast of having the main source of life in a liquid state. Hope for its discovery for a long time instilled areas of relief, very reminiscent of riverbeds. It is still not completely clear what could lead to their formation, if the Red Planet has never been liquid water. The atmosphere of Mars testifies in favor of the "dry" past. Its pressure is so insignificant that the boiling point of water falls at temperatures unusually low for the Earth, that is, it can exist here only in gaseous state. Theoretically, Mars could have had a denser atmosphere in the past, but then it would have left traces of it in the form of heavy inert gases. However, they have not been found so far.

Winds and storms

The temperature on Mars, more precisely, its differences, leads to the rapid movement of air masses in the hemisphere where winter has come. The resulting winds reach 170 m/s. On Earth, such phenomena would be accompanied by showers, but the Red Planet does not have sufficient water reserves for this. Dust storms arise here, so massive that sometimes they cover the entire planet. The rest of the time there is almost always clear weather (water is also needed to form a significant amount of clouds) and very clear air.

Despite the relatively small size of Mars and its uninhabitability, scientists have high hopes for it. Here in the future it is planned to place bases for the extraction of minerals and the implementation of various scientific activity. It is still difficult to say how real such projects are, but the continuous development of technology testifies in favor of the fact that soon humanity will be able to embody the most daring ideas.

Dust storms sweep over the surface of Mars every year. Sometimes they grow so large that they hide the planet from view. This can put future colonists in a difficult position: some storms can last for several months, blocking out sunlight and depriving solar panels of a source of energy. At present, there is no exact way to predict such storms, but according to scientists’ calculations, a strong dust storm will rage on the Red Planet in the coming months, and if this really happens, it will be much easier to track cataclysms in the future.

Most likely, global dust storms occur when Mars is closest to the Sun. According to James Shirley, an astronomer at NASA's Jet Acceleration Laboratory and author of papers on Martian storm research, the hotter the dust in the atmosphere gets, the faster it moves, so it makes sense. Sometimes a column of dust rises up to 60 kilometers into the atmosphere (for comparison, Everest is only 8,848 kilometers high). Predicting such storms is complicated primarily by the fact that we know very little about them. “On the one hand, they should not occur at all, and on the other hand, dust storms should last constantly, since Mars is well lit by the Sun and gets very hot under its rays. The reasons why storms occur periodically and irregularly are not yet known to us,” says Shirley.

A dust storm can interfere not only with the work of astronauts on the planet itself, it can simply prevent the shuttle from landing on Mars. When the atmosphere heats up and dust moves, it not only reduces visibility and hides the landing zone (which could easily land a ship in a gorge, for example), but also causes the skin to heat up due to friction, which can adversely affect ship systems. Be that as it may, the wind speed in huge dust storms is lower than on Earth: the atmosphere of Mars is much thinner than Earth's, and the wind speed does not exceed 90-120 km / h. Plus, due to the thin atmosphere, even the fastest hurricane will feel like roughly 16 km/h wind on Earth, explains Steve Hoffman, aerospace engineer at NASA's Johnson Space Center. “This kind of wind won't topple an astronaut or a rocket,” he says. However, a large storm can clog the gaps in the skin of the ship and equipment with debris, leave solar panels without a source of energy and thus seriously harm the work of astronauts and rovers. For example, the Spirit and Opportunity rovers that were caught in a dust storm in 2007 waited for weeks, only able to recharge for a few minutes a day when the storm eased and the sky briefly cleared.

How well the astronauts can prepare for a storm depends on their level of awareness. The sooner they can predict the arrival of a storm, the more chances they have to minimize the consequences of its destructive activity. One of the possible strategies could be the transition to alternative energy sources. Curiosity rover, for example, uses a radioisotope power system, getting energy from plutonium. Splitting water into hydrogen and oxygen might be a good idea, but unfortunately hydrogen is explosive and plutonium is radioactive, so neither of these methods looks particularly attractive to NASA when we are talking about the expedition with living people. In addition, there is another danger: Martian dust contains toxic perchlorates and persulfates that can penetrate suits (the dust is very fine, so it is unlikely that even on board the shuttle astronauts will be able to completely avoid contact with it in one way or another). “Any hatches, air ducts, rotating parts of the suit and gaps can become a gate for dust, which can lead to banal mechanical wear of the equipment,” Hoffman shares his concerns.

Last year, James Shirley explored how the rotation of Mars around the center solar system may be associated with the occurrence dust storms. It may seem surprising, but the center of the system is not always the Sun, although the luminary does not move away from it. The attraction of the planets sometimes drags the star with it, so it is in constant motion. Mars is also involved in this process, and scientists believe that it is the approach and separation of the planet from the Sun that causes the atmosphere to either heat up or cool down, which is why storms occur with a periodic frequency. They simulated planetary dust cycles and found that eight of the nine large dust storms that occurred during recent times, roughly in line with the expected forecasts. This knowledge will not only help space expeditions, but may also be useful for earth conditions: Shirley is sure that by studying physical phenomena on Mars, scientists will be able to correlate them with similar processes on Earth.

NASA has revealed truth and fiction about the dangers of dust storms on Mars, some of which may be visible from ground-based telescopes. This information was used in the creation of the new film "The Martian" directed by Ridley Scott. This was reported on the NASA website.

Dust tail (Photo: NASA / JPL-Caltech / University of Arizona)

This is due to the fact that the speed of the strongest winds on Mars does not exceed 27 meters per second, which is more than half the speed of some hurricane winds on Earth. In addition, the density of the Martian atmosphere is a hundred times less than that of the earth.

Dust from a 2008 storm covered the Spirit panels (Photo: NASA/JPL-Caltech/Cornell)

"The main difference between Earth and Mars is that the atmospheric pressure on the Red Planet is much lower," said plasma physicist William Farrell. "So everything [particles in Mars' atmosphere] becomes wind, but not at the same intensity [compared to Earth]," he added.

However, dust storms on Mars are not entirely harmless. Individual small dust particles can carry an electrostatic charge and "stick" to surfaces, in particular, portholes and mechanical parts of scientific equipment.

The neutralization of electrostatic charges and the elimination of dust pollution is one of the main tasks that engineers solve when designing equipment for Mars exploration.

This same dust is a big problem for solar panels. Even small dust storms can bring enough particles onto solar panels to significantly reduce the amount of solar energy.

In the movie The Martian, astronaut Whitney cleans up dust pollution from solar panels on a daily basis. NASA also notes that global storms on Mars may also lead to some dimming of the Red Planet's atmosphere.

“We were really worried about the energy of the rovers. The Spirit and Opportunity rovers, which landed on Mars in 2004, only experienced a global storm once (in 2007) and basically went out of service for a few weeks and went into survival mode,” Smith said.

Most often, global dust storms on Mars occur in the summer in the southern hemisphere of the planet. As on Earth, the seasons on the Red Planet are determined by its inclination to the plane of the orbit. However, the orbit of Mars is more elongated than that of the Earth, which means that during the Martian year one side of the planet is heated more than the other.