Cosmic radiation could put an end to future space flights. Radiation and space: what you need to know? (“Radiation” secrets that outer space hides)

Since their appearance on Earth, all organisms have existed, developed and evolved under constant exposure to radiation. Radiation is just as natural a natural phenomenon, like wind, tides, rain, etc.

Natural background radiation (NBR) was present on Earth at all stages of its formation. It was there long before life and then the biosphere appeared. Radioactivity and the accompanying ionizing radiation were a factor that influenced the current state of the biosphere, the evolution of the Earth, life on Earth and the elemental composition solar system. Any organism is exposed to the radiation background characteristic of a given area. Until the 1940s it was caused by two factors: the decay of radionuclides natural origin, located both in the habitat of a given organism, and in the organism itself, and by cosmic rays.

Sources of natural (natural) radiation are space and natural radionuclides contained in natural form and concentrations in all objects of the biosphere: soil, water, air, minerals, living organisms, etc. Any of the objects around us and we ourselves are radioactive in the absolute sense of the word.

The main dose of radiation to the population globe receives from natural sources of radiation. Most of them are such that it is absolutely impossible to avoid exposure to radiation from them. Throughout the history of the Earth different types radiation penetrates the earth's surface from space and comes from radioactive substances located in earth's crust. A person is exposed to radiation in two ways. Radioactive substances can be outside the body and irradiate it from the outside (in this case we talk about external irradiation) or they can end up in the air that a person breathes, in food or water and get inside the body (this method of irradiation is called internal).

Any inhabitant of the Earth is exposed to radiation from natural sources of radiation. This depends, in part, on where people live. Radiation levels in some places on the globe, especially where radioactive rocks occur, are significantly higher than average, and in other places they are lower. Terrestrial sources of radiation are collectively responsible for the majority of exposure to which humans are exposed through natural radiation. On average, they provide more than 5/6 of the annual effective equivalent dose received by the population, mainly due to internal exposure. The rest is contributed by cosmic rays, mainly through external irradiation.

The natural radiation background is formed by cosmic radiation (16%) and radiation created by radionuclides scattered in nature contained in the earth's crust, ground air, soil, water, plants, food, in animal and human organisms (84%). Technogenic background radiation is associated mainly with processing and transportation rocks, burning coal, oil, gas and other fossil fuels, as well as testing nuclear weapons and nuclear energy.

Natural background radiation is an integral factor environment, which has a significant impact on human life. Natural background radiation varies widely in different regions of the Earth. The equivalent dose in the human body is on average 2 mSv = 0.2 rem. Evolutionary development shows that in natural background conditions, optimal conditions for the life of humans, animals and plants. Therefore, when assessing the hazards caused by ionizing radiation, it is critical to know the nature and levels of exposure from various sources.

Since radionuclides, like any atoms, form certain compounds in nature and, in accordance with their chemical properties are part of certain minerals, the distribution of natural radionuclides in the earth’s crust is uneven. Cosmic radiation, as mentioned above, also depends on a number of factors and may differ several times. Thus, the natural background radiation is different in different places on the globe. This is related to the convention of the concept of “normal radiation background”: with altitude above sea level, the background increases due to cosmic radiation, in places where granites or thorium-rich sands come to the surface, the background radiation is also higher, and so on. Therefore, we can only talk about the average natural radiation background for a given area, territory, country, etc.

The average effective dose received by a resident of our planet from natural sources per year is 2.4 mSv .

Approximately 1/3 of this dose is formed due to external radiation (approximately equally from space and from radionuclides) and 2/3 is due to internal radiation, that is, natural radionuclides located inside our body. The average human specific activity is about 150 Bq/kg. Natural background radiation (external exposure) at sea level averages about 0.09 μSv/h. This corresponds to approximately 10 µR/h.

Cosmic radiation is a stream of ionizing particles that falls to Earth from outer space. The composition of cosmic radiation includes:

Cosmic radiation consists of three components that differ in origin:

1) radiation from particles captured by the Earth’s magnetic field;

2) galactic cosmic radiation;

3) corpuscular radiation from the Sun.

Radiation from charged particles captured by the Earth's magnetic field - at a distance of 1.2-8 Earth radii there are so-called radiation belts containing protons with an energy of 1-500 MeV (mainly 50 MeV), electrons with an energy of about 0.1-0.4 MeV and a small amount of alpha particles.

Compound. Galactic cosmic rays are composed primarily of protons (79%) and alpha particles (20%), reflecting the abundance of hydrogen and helium in the Universe. Among the heavy ions highest value have iron ions due to their relatively high intensity and large atomic number.

Origin. The sources of galactic cosmic rays are stellar flares, supernova explosions, pulsar acceleration, explosions of galactic nuclei, etc.

Lifetime. The lifetime of particles in cosmic radiation is about 200 million years. Particle retention occurs due to magnetic field interstellar space.

Interaction with the atmosphere . Entering the atmosphere, cosmic rays interact with atoms of nitrogen, oxygen and argon. Particles collide with electrons more often than with nuclei, but high-energy particles lose little energy. In collisions with nuclei, particles are almost always eliminated from the flow, so the weakening of primary radiation is almost entirely due to nuclear reactions.

When protons collide with nuclei, neutrons and protons are knocked out of the nuclei, and nuclear fission reactions occur. The resulting secondary particles have significant energy and themselves induce the same nuclear reactions, i.e., a whole cascade of reactions is formed, a so-called broad atmospheric shower is formed. A single high-energy primordial particle can produce a shower of ten successive generations of reactions producing millions of particles.

New nuclei and nucleons, which make up the nuclear-active component of radiation, are formed mainly in the upper layers of the atmosphere. In its lower part, the flow of nuclei and protons is significantly weakened due to nuclear collisions and further ionization losses. At sea level it generates only a few percent of the dose rate.

Cosmogenic radionuclides

As a result of nuclear reactions occurring under the influence of cosmic rays in the atmosphere and partly in the lithosphere, radioactive nuclei are formed. Of these, the greatest contribution to dose creation is made by (β-emitters: 3 H (T 1/2 = 12.35 years), 14 C (T 1/2 = 5730 years), 22 Na (T 1/2 = 2.6 years) - entering the human body with food. As follows from the data presented, the largest contribution to radiation is made by carbon-14. An adult consumes ~ 95 kg of carbon per year with food.

Solar radiation, consisting of electromagnetic radiation up to the X-ray range, protons and alpha particles;

Listed species radiations are primary, they almost completely disappear at an altitude of about 20 km due to interaction with top layers atmosphere. In this case, secondary cosmic radiation is formed, which reaches the surface of the Earth and affects the biosphere (including humans). Secondary radiation includes neutrons, protons, mesons, electrons and photons.

The intensity of cosmic radiation depends on a number of factors:

Changes in the flux of galactic radiation,

Sun activity,

Geographic latitude,

Altitudes above sea level.

Depending on the altitude, the intensity of cosmic radiation increases sharply.

Radionuclides of the earth's crust.

Long-lived (with a half-life of billions of years) isotopes that did not have time to decay during the existence of our planet are scattered in the earth's crust. They probably formed simultaneously with the formation of the planets of the Solar System (relatively short-lived isotopes decayed completely). These isotopes are called natural radioactive substances, this means those that were formed and are constantly being re-formed without human participation. As they decay, they form intermediate, also radioactive, isotopes.

External sources of radiation are more than 60 natural radionuclides found in the Earth's biosphere. Natural radioactive elements are contained in relatively small quantities in all the shells and core of the Earth. Of particular importance for humans are the radioactive elements of the biosphere, i.e. that part of the Earth’s shell (litho-, hydro- and atmosphere) where microorganisms, plants, animals and humans are located.

For billions of years, there was a constant process of radioactive decay of unstable atomic nuclei. As a result of this, the total radioactivity of the Earth's substance and rocks gradually decreased. Relatively short-lived isotopes decayed completely. Mainly elements with half-lives measured in billions of years have been preserved, as well as relatively short-lived secondary products of radioactive decay, forming successive chains of transformations, the so-called families of radioactive elements. In the earth's crust, natural radionuclides can be more or less evenly dispersed or concentrated in the form of deposits.

Natural (natural) radionuclides can be divided into three groups:

Radionuclides belonging to radioactive families (series),

Other (not belonging to radioactive families) radionuclides that became part of the earth's crust during formation of the planet,

Radionuclides formed under the influence of cosmic radiation.

During the formation of the Earth, radionuclides, along with stable nuclides, also became part of its crust. Most of these radionuclides belong to the so-called radioactive families (series). Each row is a chain of consecutive radioactive transformations, when the nucleus formed during the decay of the mother nucleus also, in turn, decays, again generating an unstable nucleus, etc. The beginning of such a chain is a radionuclide that is not formed from another radionuclide, but is contained in the earth’s crust and biosphere from the moment they birth. This radionuclide is called the ancestor and the entire family (series) is named after it. In total, there are three ancestors in nature - uranium-235, uranium-238 and thorium-232, and, accordingly, three radioactive series - two uranium and thorium. All series end with stable isotopes of lead.

Thorium has the longest half-life (14 billion years), so it has been preserved almost completely since the accretion of the Earth. Uranium-238 decayed to a large extent, the vast majority of uranium-235 decayed, and the isotope neptunium-232 decayed entirely. For this reason, there is a lot of thorium in the earth's crust (almost 20 times more than uranium), and uranium-235 is 140 times less than uranium-238. Since the ancestor of the fourth family (neptunium) has completely disintegrated since the accretion of the Earth, it is almost absent from rocks. Neptunium has been found in trace amounts in uranium ores. But its origin is secondary and is due to the bombardment of uranium-238 nuclei by cosmic ray neutrons. Neptunium is now produced using artificial nuclear reactions. For an ecologist it is of no interest.

About 0.0003% (according to various sources 0.00025-0.0004%) of the earth's crust is uranium. That is, one cubic meter of the most ordinary soil contains an average of 5 grams of uranium. There are places where this amount is thousands of times greater - these are uranium deposits. In cubic meter sea ​​water contains about 1.5 mg of uranium. This natural chemical element is represented by two isotopes -238U and 235U, each of which is the ancestor of its own radioactive series. The vast majority of natural uranium (99.3%) is uranium-238. This radionuclide is very stable, the probability of its decay (namely, alpha decay) is very small. This probability is characterized by a half-life of 4.5 billion years. That is, since the formation of our planet, its quantity has decreased by half. From this, in turn, it follows that the background radiation on our planet used to be higher. Chains of radioactive transformations that generate natural radionuclides of the uranium series:

The radioactive series includes both long-lived radionuclides (that is, radionuclides with a long half-life) and short-lived ones, but all radionuclides in the series exist in nature, even those that decay quickly. This is due to the fact that over time, an equilibrium has been established (the so-called “secular equilibrium”) - the decay rate of each radionuclide is equal to the rate of its formation.

There are natural radionuclides that entered the earth's crust during the formation of the planet and that do not belong to the uranium or thorium series. First of all, it is potassium-40. The content of 40 K in the earth's crust is about 0.00027% (mass), half-life is 1.3 billion years. The daughter nuclide, calcium-40, is stable. Potassium-40 is found in significant quantities in plants and living organisms and makes a significant contribution to the total dose of internal radiation to humans.

Natural potassium contains three isotopes: potassium-39, potassium-40 and potassium-41, of which only potassium-40 is radioactive. The quantitative ratio of these three isotopes in nature looks like this: 93.08%, 0.012% and 6.91%.

Potassium-40 breaks down in two ways. About 88% of its atoms experience beta radiation and become calcium-40 atoms. The remaining 12% of atoms, experiencing K-capture, turn into argon-40 atoms. The potassium-argon method for determining the absolute age of rocks and minerals is based on this property of potassium-40.

The third group of natural radionuclides consists of cosmogenic radionuclides. These radionuclides are formed under the influence of cosmic radiation from stable nuclides as a result of nuclear reactions. These include tritium, beryllium-7, carbon-14, sodium-22. For example, nuclear reactions of the formation of tritium and carbon-14 from nitrogen under the influence of cosmic neutrons:

Special place Carbon ranks among natural radioisotopes. Natural carbon consists of two stable isotopes, among which carbon-12 predominates (98.89%). The rest is almost entirely carbon-13 (1.11%).

In addition to the stable isotopes of carbon, five more radioactive ones are known. Four of them (carbon-10, carbon-11, carbon-15 and carbon-16) have very short half-lives (seconds and fractions of a second). A fifth radioisotope, carbon-14, has a half-life of 5,730 years.

In nature, the concentration of carbon-14 is extremely low. For example, in modern plants there is one atom of this isotope for every 10 9 atoms of carbon-12 and carbon-13. However, with the advent of atomic weapons and nuclear technology, carbon-14 is produced artificially by the interaction of slow neutrons with atmospheric nitrogen, so its quantity is constantly growing.

There is some convention regarding what background is considered “normal”. So, with the “average planetary” annual effective dose per person 2.4 mSv; in many countries this value is 7-9 mSv/year. That is, from time immemorial, millions of people have lived in conditions of natural dose loads that are several times higher than the statistical average. Medical research and demographic statistics show that this does not affect their lives in any way, does not have any negative influence on their health and the health of their offspring.

Speaking about the conventionality of the concept of “normal” natural background, we can also point out a number of places on the planet where the level of natural radiation exceeds the statistical average not only several times, but also tens of times (table); tens and hundreds of thousands of inhabitants are exposed to this effect. And this is also the norm, this also does not affect their health in any way. Moreover, many areas with increased background radiation have been places of mass tourism for centuries ( sea ​​coasts) and recognized resorts (Caucasian Mineral water, Karlovy Vary, etc.).

As already mentioned, as soon as the Americans began their space program, they scientist James Van Allen has done enough important discovery. The first American artificial satellite they launched into orbit was much smaller than the Soviet one, but Van Allen thought of attaching a Geiger counter to it. Thus, what was expressed at the end of the 19th century was officially confirmed. The outstanding scientist Nikola Tesla hypothesized that the Earth is surrounded by a belt of intense radiation.

Photograph of Earth by astronaut William Anders

during the Apollo 8 mission (NASA archives)

Tesla, however, was considered a great eccentric, and even crazy by academic science, so his hypotheses about the giant giant generated by the Sun electric charge have been lying under the carpet for a long time, and the term “solar wind” caused nothing but smiles. But thanks to Van Allen, Tesla's theories were revived. At the instigation of Van Allen and a number of other researchers, it was established that radiation belts in space begin at 800 km above the Earth's surface and extend up to 24,000 km. Since the radiation level there is more or less constant, the incoming radiation should be approximately equal to the outgoing radiation. Otherwise, it would either accumulate until it “baked” the Earth, as in an oven, or it would dry up. On this occasion, Van Allen wrote: “Radiation belts can be compared to a leaky vessel, which is constantly replenished from the Sun and flows into the atmosphere. A large portion of solar particles overflows the vessel and splashes out, especially in the polar zones, leading to auroras, magnetic storms and other similar phenomena."

Radiation from the Van Allen belts depends on the solar wind. In addition, they appear to focus or concentrate this radiation within themselves. But since they can only concentrate in themselves what came directly from the Sun, one more question remains open: how much radiation is in the rest of the cosmos?

Orbits of atmospheric particles in the exosphere(dic.academic.ru)

The Moon does not have Van Allen belts. She also has no protective atmosphere. It is open to all solar winds. If a strong solar flare had occurred during the lunar expedition, a colossal flow of radiation would have incinerated both the capsules and the astronauts on the part of the lunar surface where they spent their day. This radiation is not just dangerous - it is deadly!

In 1963, Soviet scientists told the famous British astronomer Bernard Lovell that they did not know a way to protect cosmonauts from lethal impact cosmic radiation. This meant that even much thicker walled metal shells Russian devices could not cope with the radiation. How could the thinnest (almost like foil) metal used in American capsules protect astronauts? NASA knew this was impossible. The space monkeys died less than 10 days after returning, but NASA has never told us the true cause of their demise.

Monkey-astronaut (RGANT archive)

Most people, even those knowledgeable in space, are not aware of the existence of deadly radiation permeating its expanses. Oddly enough (or maybe just for reasons that can be guessed), in the American Illustrated Encyclopedia space technology“The phrase “cosmic radiation” does not appear even once. And in general, American researchers (especially those associated with NASA) avoid this topic a mile away.

Meanwhile, Lovell, after talking with Russian colleagues who were well aware of cosmic radiation, sent the information he had to NASA administrator Hugh Dryden, but he ignored it.

One of the astronauts who allegedly visited the Moon, Collins, mentioned cosmic radiation only twice in his book:

"At least the moon was far beyond earth belts Van Allen, which foreshadowed a good dose of radiation for those who were there, and a fatal dose for those who lingered.”

“Thus, the Van Allen radiation belts surrounding the Earth and the possibility of solar flares require understanding and preparation to avoid exposing the crew to increased doses of radiation.”

So what does “understand and prepare” mean? Does this mean that beyond the Van Allen belts, the rest of space is free of radiation? Or did NASA have a secret strategy for sheltering from solar flares after adopting final decision about the expedition?

NASA claimed that it could simply predict solar flares, and therefore sent astronauts to the Moon when flares were not expected and the radiation danger to them was minimal.

While Armstrong and Aldrin were doing work in outer space

on the surface of the moon, Michael Collins

placed in orbit (NASA archive)

However, other experts say: “It is only possible to predict the approximate date of future maximum radiation and its density.”

The Soviet cosmonaut Leonov finally went out in 1966. open space- however, in a super-heavy lead suit. But after just three years American astronauts jumped on the surface of the Moon, and not at all in super-heavy spacesuits, but rather quite the opposite! Maybe over the years, specialists from NASA have managed to find some kind of ultra-light material that reliably protects against radiation?

However, researchers suddenly find out that at least Apollo 10, Apollo 11 and Apollo 12 set off precisely during those periods when the number of sunspots and corresponding solar Activity were approaching the maximum. The generally accepted theoretical maximum of solar cycle 20 lasted from December 1968 to December 1969. During this period, the Apollo 8, Apollo 9, Apollo 10, Apollo 11, and Apollo 12 missions supposedly moved beyond the protection zone of the Van Allen belts and entered cislunar space.

Further study of monthly graphs showed that single solar flares are a random phenomenon, occurring spontaneously over an 11-year cycle. It also happens that in the “low” period of the cycle it happens a large number of outbreaks in a short period of time, and during the “high” period - a very small number. But what is important is that it is very strong flares can occur at any time during the cycle.

During the Apollo era, American astronauts spent a total of almost 90 days in space. Since radiation from unpredictable solar flares reaches the Earth or Moon in less than 15 minutes, the only way to protect against it would be to use lead containers. But if the rocket’s power was enough to lift such an extra weight, then why was it necessary to go into space in tiny capsules (literally 0.1 mm of aluminum) at a pressure of 0.34 atmospheres?

This is despite the fact that even a thin layer of protective coating, called “mylar,” according to the Apollo 11 crew, turned out to be so heavy that it had to be urgently removed from the lunar module!

It seems that NASA selected special guys for lunar expeditions, albeit adjusted for circumstances, cast not from steel, but from lead. The American researcher of the problem, Ralph Rene, was not too lazy to calculate how often each of the supposedly completed lunar expeditions should have been affected by solar activity.

By the way, one of the authoritative employees of NASA (distinguished physicist, by the way) Bill Modlin, in his work “Prospects for Interstellar Travel,” frankly reported: “Solar flares can emit GeV protons in the same energy range as most cosmic particles, but much more intense . The increase in their energy with increased radiation poses a particular danger, since GeV protons penetrate several meters of material... Solar (or stellar) flares with the emission of protons are a periodically occurring very serious danger in interplanetary space, which provides a radiation dose of hundreds of thousands of roentgens in a few hours at the distance from the Sun to the Earth. This dose is lethal and millions of times higher than permissible. Death can occur after 500 roentgens in a short period of time.”

Yes, brave ones American guys then they were supposed to shine worse than the fourth Chernobyl power unit. “Cosmic particles are dangerous, they come from all directions and require a minimum of two meters of dense shielding around any living organisms.” But the space capsules that NASA demonstrates to this day were just over 4 m in diameter. With the thickness of the walls recommended by Modlin, the astronauts, even without any equipment, would not have fit into them, not to mention the fact that there would not have been enough fuel to lift such capsules. But, obviously, neither the leadership of NASA nor the astronauts they sent to the Moon read their colleague’s books and, being blissfully unaware, overcame all the thorns on the road to the stars.

However, maybe NASA actually developed some kind of ultra-reliable spacesuits for them, using (obviously, very secret) ultra-light material that protects against radiation? But why wasn’t it used anywhere else, as they say, for peaceful purposes? Well, okay, they didn’t want to help the USSR with Chernobyl: after all, perestroika had not yet begun. But, for example, in 1979, in the same USA, a major reactor unit accident occurred at the Three Mile Island nuclear power plant, which led to a meltdown of the reactor core. So why didn’t the American liquidators use space suits based on the much-advertised NASA technology, costing no less than $7 million, to eliminate this delayed-action nuclear mine on their territory?..

Such a concept as solar radiation has become known quite a long time ago. As numerous studies have shown, it is not always responsible for increasing the level of air ionization.

This article is intended for persons over 18 years of age

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Cosmic radiation: truth or myth?

Cosmic rays are radiation that appears during a supernova explosion, as well as as a consequence of thermonuclear reactions in the Sun. The different nature of the origin of the rays also affects their basic characteristics. Cosmic rays that penetrate from space outside our solar system can be divided into two types - galactic and intergalactic. The latter species remains the least studied, since the concentration of primary radiation in it is minimal. That is special significance intergalactic radiation does not, since it is completely neutralized in our atmosphere.

Unfortunately, little can be said about the rays that came to us from our galaxy called Milky Way. Despite the fact that its size exceeds 10,000 light years, any changes in the radiation field at one end of the galaxy will immediately reverberate at the other.

The dangers of radiation from space

Direct cosmic radiation is destructive to a living organism, so its influence is extremely dangerous for humans. Fortunately, our Earth is reliably protected from these space aliens by a dense dome of the atmosphere. It serves as an excellent protection for all life on earth, as it neutralizes direct cosmic radiation. But not completely. When it collides with air, it breaks up into smaller particles of ionizing radiation, each of which enters into an individual reaction with its atoms. Thus, high-energy radiation from space is weakened and forms secondary radiation. At the same time, it loses its lethality - the level of radiation becomes approximately the same as in X-rays. But don’t be alarmed—this radiation completely disappears as it passes through the Earth’s atmosphere. Whatever the sources of cosmic rays, and whatever power they have, the danger to a person who is on the surface of our planet is minimal. It can only cause tangible harm to astronauts. They are exposed to direct cosmic radiation, since they do not have natural protection in the form of an atmosphere.

The energy released by cosmic rays primarily affects the Earth's magnetic field. Charged ionizing particles literally bombard it and become the cause of the most beautiful atmospheric phenomenon - . But that's not all - radioactive particles, due to their nature, can cause malfunctions in various electronics. And if in the last century this did not cause much discomfort, in our time it is a very serious problem, since the most important aspects of modern life are tied to electricity.

Humans are also susceptible to these visitors from space, although the mechanism of action of cosmic rays is very specific. Ionized particles (that is, secondary radiation) affect the Earth's magnetic field, thereby causing storms in the atmosphere. Everyone knows that the human body consists of water, which is very susceptible to magnetic vibrations. Thus, cosmic radiation affects the cardiovascular system and causes poor health in weather-sensitive people. This is, of course, unpleasant, but by no means fatal.

What protects the Earth from solar radiation?

The Sun is a star, in the depths of which various thermonuclear reactions constantly take place, which are accompanied by strong energy emissions. These charged particles are called solar wind and have a strong influence on our Earth, or rather on its magnetic field. It is with it that ionized particles interact, which form the basis of the solar wind.

According to the latest research by scientists from around the world, the plasma shell of our planet plays a special role in neutralizing the solar wind. This happens as follows: solar radiation collides with the Earth's magnetic field and is scattered. When there is too much of it, the plasma shell takes the blow, and an interaction process similar to a short circuit occurs. The consequence of such a struggle may be cracks in the protective shield. But nature has provided for this too - streams of cold plasma rise from the surface of the Earth and rush to places with weakened protection. Thus, the magnetic field of our planet reflects the impact from space.

But it is worth stating the fact that solar radiation, unlike cosmic radiation, still reaches the Earth. At the same time, you should not worry in vain, because in essence this is the energy of the Sun, which should fall on the surface of our planet in a dispersed state. Thus, it heats the Earth's surface and helps develop life on it. Thus, it is worth clearly distinguishing between different types of radiation, because some of them not only have no negative impact, but also necessary for the normal functioning of living organisms.

However, on Earth not all substances are equally susceptible to solar radiation. There are surfaces that absorb it more than others. These are, as a rule, underlying surfaces with a minimum level of albedo (the ability to reflect solar radiation) - earth, forest, sand.

Thus, the temperature on the Earth's surface, as well as the duration daylight hours directly depends on how much solar radiation is absorbed by the atmosphere. I would like to say that the bulk of energy still reaches the surface of our planet, because the air shell of the Earth serves as a barrier only for rays of the infrared spectrum. But UV rays are only partially neutralized, which leads to some problems with skin in people and animals.

The influence of solar radiation on the human body

When exposed to rays of the infrared spectrum of solar radiation, a thermal effect clearly manifests itself. It promotes vasodilation, stimulates the cardiovascular system, and activates skin respiration. As a result, the main systems of the body relax, and the production of endorphins (hormones of happiness), which have an analgesic and anti-inflammatory effect, increases. Heat also affects metabolic processes, activating metabolism.

Light radiation from solar radiation has a significant photochemical effect, which activates important processes in tissues. This type of solar radiation allows a person to use one of the most important systems touch of the external world - vision. It is these quanta that we should be grateful for the fact that we see everything in color.

Important influencing factors

Solar radiation of the infrared spectrum also stimulates brain activity and is responsible for human mental health. It is also important that this particular type of solar energy affects our biological rhythms, that is, the phases of active activity and sleep.

Without light particles, many vital processes would be at risk, which could lead to the development of various diseases, including insomnia and depression. Also, with minimal contact with solar light radiation, a person’s ability to work is significantly reduced, and most processes in the body slow down.

UV radiation is quite useful for our body, since it also triggers immunological processes, that is, it stimulates the body's defenses. It is also needed for the production of porphyrite, an analogue of plant chlorophyll in our skin. However, excess UV rays can cause burns, so it is very important to know how to properly protect yourself from this during periods of maximum solar activity.

As you can see, the benefits of solar radiation for our body are undeniable. Many people are very worried about whether food absorbs this type of radiation and whether it is dangerous to eat contaminated foods. I repeat - solar energy has nothing to do with cosmic or atomic radiation, which means there is no need to be afraid of it. And it would be pointless to avoid it... No one has yet looked for a way to escape from the Sun.

Space is radioactive. It is simply impossible to hide from radiation. Imagine yourself standing in the middle sandstorm, and a whirlpool of small pebbles constantly swirls around you, hurting your skin. This is what cosmic radiation looks like. And this radiation causes considerable harm. But the problem is that, unlike pebbles and pieces of earth, ionizing radiation does not bounce off human flesh. It goes through her like a cannonball goes through a building. And this radiation causes considerable harm.

Last week, scientists at the University of Rochester Medical Center published a study showing that long-term exposure to galactic radiation, which astronauts may be exposed to on Mars, may increase the risk of Alzheimer's disease.

Reading media reports about this study made me curious. We've been sending people into space for more than half a century. We have the opportunity to follow an entire generation of astronauts - how these people grow old and die. And we constantly monitor the health status of those who fly into space today. Scientific works, like those carried out at the University of Rochester, are carried out on laboratory animals such as mice and rats. They are designed to help us prepare for the future. But what do we know about the past? Has radiation affected people who have already been in space? How does it affect those in orbit at the moment?

There is one key difference between the astronauts of today and the astronauts of the future. The difference is the Earth itself.

Galactic cosmic radiation, sometimes called cosmic radiation, is what causes the greatest concern among researchers. It consists of particles and pieces of atoms that could have been created as a result of the formation of a supernova. Most of this radiation, approximately 90%, consists of protons torn from hydrogen atoms. These particles fly through the galaxy at almost the speed of light.

And then they strike the Earth. Our planet has a couple of defense mechanisms that protect us from the effects of cosmic radiation. First, the Earth's magnetic field repels some particles and blocks others completely. Particles that have overcome this barrier begin to collide with atoms in our atmosphere.

If you throw a large Lego tower down the stairs, it will break into small pieces that will fly off with each new step. About the same thing happens in our atmosphere and with galactic radiation. Particles collide with atoms and break apart to form new particles. These new particles again hit something and again fall apart. With every step they take, they lose energy. The particles slow down and gradually weaken. By the time they “stop” on the surface of the Earth, they no longer have the powerful reserve of galactic energy that they possessed before. This radiation is much less dangerous. A small Lego piece hits much weaker than a tower assembled from them.

All those astronauts we have sent into space have benefited from Earth's protective barriers in many ways, at least in part. Francis Cucinotta told me about this. He is the scientific director of NASA's program to study the effects of radiation on humans. This is exactly the guy who can tell you how harmful radiation is to astronauts. According to him, with the exception of the Apollo flights to the Moon, man is present in space within the influence of the Earth's magnetic field. International space station, for example, is located above the atmosphere, but still deep in the first echelon of defense. Our astronauts are not fully exposed to cosmic radiation.

In addition, they are under such influence for a fairly short time. The longest flight into space lasted just over a year. And this is important because the damage from radiation has a cumulative effect. You risk much less when you spend six months on the ISS than when you go on a (still theoretical) multi-year journey to Mars.

But what's interesting and quite alarming, Cucinotta told me, is that even with all these protection mechanisms in place, we're seeing radiation negatively impact astronauts.

A very unpleasant thing is cataracts - changes in the lens of the eye that cause clouding. Because less light enters the eye through a cloudy lens, people with cataracts see less well. In 2001, Cucinotta and his colleagues examined data from an ongoing study of astronaut health and came to the following conclusion. Astronauts who were exposed to a higher dose of radiation (because they flew more times in space or because of the nature of their missions*) were more likely to develop cataracts than those who received a lower dose of radiation.

Surely there is also increased danger cancer, although it is difficult to analyze this danger quantitatively and accurately. The fact is that we do not have epidemiological data on what type of radiation astronauts are exposed to. We know the number of cancer cases after the atomic bombing of Hiroshima and Nagasaki, but this radiation is not comparable to galactic radiation. In particular, Cucinotta is most concerned about high-frequency ions—high-atomic, high-energy particles.

These are very heavy particles and they move very quickly. On the surface of the Earth we do not experience their effects. They are sifted out, slowed down and broken into pieces defense mechanisms of our planet. However, high-frequency ions can cause more harm and more varied harm than the radiation with which radiologists are familiar. We know this because scientists compare blood samples from astronauts before and after spaceflight.

Cucinotta calls this a pre-flight check. Scientists take a blood sample from an astronaut before going into orbit. When an astronaut is in space, scientists divide the drawn blood into parts and expose it to varying degrees of gamma radiation. This is like the harmful radiation that we sometimes encounter on Earth. Then, when the astronaut returns, they compare these gamma-rayed blood samples with what actually happened to him in space. “We're seeing two to threefold differences across different astronauts,” Cucinotta told me.

Even if interplanetary flights were a reality, scientists are increasingly saying that the human body is purely biological point More and more dangers await our vision. Experts call hard cosmic radiation one of the main dangers. On other planets, for example on Mars, this radiation will be such that it will significantly accelerate the onset of Alzheimer's disease.

"Cosmic radiation poses a very significant threat to future astronauts. The possibility that cosmic radiation exposure could lead to health problems such as cancer has long been recognized," says Kerry O'Banion, a neuroscience doctor from Medical center at the University of Rochester. "Our experiments also reliably established that hard radiation also provokes an acceleration of changes in the brain associated with Alzheimer's disease."

According to scientists, everything space literally permeated with radiation, while the thick earth's atmosphere protects our planet from it. Participants in short-term flights to the ISS can already feel the effects of radiation, although formally they are in low orbit, where the protective dome of Earth’s gravity is still working. Radiation is especially active at those moments when flares occur on the Sun with subsequent emissions of radiation particles.

Scientists say that NASA is already working closely on various approaches related to protecting humans from space radiation. The space agency first began funding “radiation research” 25 years ago. Currently, a significant part of the initiatives in this area is related to research on how to protect future marsonauts from harsh radiation on the Red Planet, where there is no such atmospheric dome as on Earth.

Already, experts say with a very high probability that Martian radiation provokes cancer. There are even larger amounts of radiation near asteroids. Let us remind you that NASA plans a mission to an asteroid with human participation for 2021, and to Mars no later than 2035. A trip to Mars and back, with some time spent there, could take about three years.

As NASA said, it has now been proven that cosmic radiation provokes, in addition to cancer, also diseases of cardio-vascular system, musculoskeletal and endocrine. Now experts from Rochester have identified another vector of danger: research has found that high doses of cosmic radiation provoke diseases associated with neurodegeneration, in particular, they activate processes that contribute to the development of Alzheimer's disease. Experts also studied how cosmic radiation affects the human central nervous system.

Based on experiments, experts have established that radioactive particles in space have in their structure the nuclei of iron atoms, which have phenomenal penetrating ability. This is why it is surprisingly difficult to defend against them.

On Earth, researchers simulated cosmic radiation at the American Brookhaven National Laboratory on Long Island, where a special accelerator is located elementary particles. Through experiments, researchers determined the time frame during which the disease occurs and progresses. However, so far the researchers have been conducting experiments on laboratory mice, exposing them to doses of radiation comparable to those that people would receive during a flight to Mars. After the experiments, almost all mice suffered disturbances in the functioning of the cognitive system of the brain. Disturbances in the functioning of the cardiovascular system were also noted. Foci of accumulation of beta-amyloid, a protein that is a sure sign of impending Alzheimer's disease, have been identified in the brain.

Scientists say they don't yet know how to combat space radiation, but they are confident that radiation is a factor that deserves the most serious attention when planning future space flights.