Space is radioactive. It is simply impossible to hide from radiation. Imagine that you are standing in the middle of a 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 work such as that carried out at the University of Rochester is 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 of the 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. The International Space Station, for example, is above the atmosphere, but still deep in the first line 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 a little more than 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.
There is probably also an increased risk of cancer, although it is difficult to analyze this risk quantitatively and precisely. 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 particle 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 screened out, inhibited and broken into pieces by the protective 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.
Who hasn’t dreamed of flying into space, even knowing what cosmic radiation is? At least fly to Earth orbit or to the Moon, or even better - further away, to some Orion. In fact, the human body is very little adapted to such travel. Even when flying into orbit, astronauts face many dangers that threaten their health and sometimes their lives. Everyone watched the cult TV series Star Trek. One of the wonderful characters there gave a very exact description such a phenomenon as cosmic radiation. “It's danger and disease in darkness and silence,” said Leonard McCoy, aka Bony, aka Bonesetter. It is very difficult to be more precise. Cosmic radiation during travel will make a person tired, weak, sick, and suffering from depression.
Feelings in flight
The human body is not adapted to life in airless space, since evolution did not include such abilities in its arsenal. Books have been written about this, this issue is studied in detail by medicine, centers have been created all over the world to study the problems of medicine in space, in extreme conditions, at high altitudes. Of course, it’s funny to watch an astronaut smile on the screen while they float in the air various items. In fact, his expedition is much more serious and fraught with consequences than it seems to an ordinary inhabitant from Earth, and it is not only cosmic radiation that creates trouble.
At the request of journalists, astronauts, engineers, scientists, who have experienced first-hand everything that happens to a person in space, spoke about the sequence of various new sensations in an artificially created environment alien to the body. Literally ten seconds after the start of the flight, an unprepared person loses consciousness because the acceleration of the spacecraft increases, separating it from the launch complex. Man is not yet as strong as in outer space, senses cosmic rays - radiation is absorbed by the atmosphere of our planet.
Major troubles
But there are also enough overloads: a person becomes four times heavier than his own weight, he is literally pressed into a chair, it is difficult to even move his arm. Everyone has seen these special chairs, for example, in the Soyuz spacecraft. But not everyone understood why the astronaut had such a strange pose. However, it is necessary because overloads send almost all the blood in the body down to the legs, and the brain is left without blood supply, which is why fainting occurs. But a chair invented in the Soviet Union helps to avoid at least this trouble: the position with raised legs forces the blood to supply oxygen to all parts of the brain.
Ten minutes after the start of the flight, the lack of gravity will cause a person to almost lose their sense of balance, orientation and coordination in space; a person may not even be able to track moving objects. He feels nauseous and vomits. Cosmic rays can cause the same thing - the radiation here is already much stronger, and if there is a plasma ejection into the sun, the threat to the lives of astronauts in orbit is real, even airline passengers can suffer during a flight to high altitude. Vision changes, swelling and changes occur in the retina of the eyes, and the eyeball becomes deformed. A person becomes weak and cannot complete the tasks that are assigned to him.
Puzzles
However, from time to time people also feel high cosmic radiation on Earth; for this they do not necessarily have to travel into outer space. Our planet is constantly bombarded by rays of cosmic origin, and scientists suggest that our atmosphere does not always provide sufficient protection. There are many theories that give these energetic particles a power that greatly limits the chances of planets having life on them. In many ways, the nature of these cosmic rays is still an insoluble mystery for our scientists.
Subatomic charged particles in space move almost at the speed of light, they have already been recorded several times on satellites, and even on These nuclei chemical elements, protons, electrons, photons and neutrinos. It is also possible that particles - heavy and superheavy - may be present in the attack of cosmic radiation. If they could be discovered, a number of contradictions in cosmological and astronomical observations would be resolved.
Atmosphere
What protects us from cosmic radiation? Only our atmosphere. Cosmic rays, threatening the death of all living things, collide in it and generate streams of other particles - harmless, including muons, much heavier relatives of electrons. A potential danger still exists, since some particles reach the Earth's surface and penetrate many tens of meters into its depths. The level of radiation that any planet receives indicates its suitability or unsuitability for life. The high energy that cosmic rays carry with them far exceeds the radiation from its own star, because the energy of protons and photons, for example, of our Sun, is lower.
And with high life is impossible. On Earth, this dose is controlled by the strength of the planet’s magnetic field and the thickness of the atmosphere; they significantly reduce the danger of cosmic radiation. For example, there could well be life on Mars, but the atmosphere there is negligible, there is no magnetic field of its own, and therefore there is no protection from cosmic rays that penetrate the entire space. The level of radiation on Mars is enormous. And the influence of cosmic radiation on the planet’s biosphere is such that all life on it dies.
What's more important?
We are lucky, we have both a thick atmosphere enveloping the Earth and our own fairly powerful magnetic field that absorbs harmful particles that reach the earth’s crust. I wonder whose protection for the planet works more actively - the atmosphere or the magnetic field? Researchers are experimenting by creating models of planets, either providing them with a magnetic field or not. And the magnetic field itself differs in strength between these models of planets. Previously, scientists were sure that it was the main protection against cosmic radiation, since they controlled its level on the surface. However, it was discovered that the amount of radiation is determined to a greater extent by the thickness of the atmosphere that covers the planet.
If the magnetic field on Earth is “turned off,” the radiation dose will only double. This is a lot, but even for us it will have a rather insignificant effect. And if you leave the magnetic field and remove the atmosphere to one tenth of its total amount, then the dose will increase deadly - by two orders of magnitude. Terrible cosmic radiation will kill everything and everyone on Earth. Our Sun is a yellow dwarf star, and it is around them that the planets are considered the main contenders for habitability. These stars are relatively dim, there are many of them, about eighty percent of the total number of stars in our Universe.
Space and evolution
Theorists have calculated that such planets orbiting yellow dwarfs, which are in zones suitable for life, have much weaker magnetic fields. This is especially true for the so-called super-Earths - large rocky planets with a mass ten times greater than our Earth. Astrobiologists were confident that weak magnetic fields significantly reduced the chances of habitability. And now new discoveries suggest that this is not such a large-scale problem as people used to think. The main thing would be the atmosphere.
Scientists are comprehensively studying the effect of increasing radiation on existing living organisms - animals, as well as on a variety of plants. Radiation-related research involves exposing them to varying degrees of radiation, from low to extreme levels, and then determining whether they will survive and how differently they will feel if they do. Microorganisms affected by gradually increasing radiation may show us how evolution took place on Earth. It is cosmic rays high radiation they once forced the future man to get off the palm tree and study space. And humanity will never return to the trees again.
Cosmic radiation 2017
At the beginning of September 2017, our entire planet was greatly alarmed. The sun suddenly ejected tons of solar material after the merger of two large groups dark spots. And this emission was accompanied by X-class flares, which forced the planet’s magnetic field to literally wear out. A large magnetic storm followed, causing illness in many people, as well as extremely rare, almost unprecedented natural phenomena on Earth. For example, near Moscow and Novosibirsk, powerful images of the northern lights were recorded that had never been seen in these latitudes. However, the beauty of such phenomena did not obscure the consequences of a deadly solar flare that permeated the planet with cosmic radiation, which turned out to be truly dangerous.
Its power was close to the maximum, X-9.3, where the letter is the class (extremely large flash), and the number is the flash strength (out of ten possible). Along with this release came the threat of system failure space communications and all the equipment located on the Cosmonauts were forced to wait out this stream of terrible cosmic radiation carried by cosmic rays in a special shelter. The quality of communications during these two days deteriorated significantly in both Europe and America, precisely where the flow of charged particles from space was directed. About a day before the particles reached the Earth's surface, a warning was issued about cosmic radiation, which sounded on every continent and in every country.
Power of the Sun
The energy emitted by our star into the surrounding space is truly enormous. Within a few minutes, many billions of megatons, if calculated in TNT equivalent, fly into space. Humanity will be able to produce so much energy at current rates only in a million years. Just a fifth of the total energy emitted by the Sun per second. And this is our small and not too hot dwarf! If you just imagine how much destructive energy other sources of cosmic radiation produce, next to which our Sun will seem like an almost invisible grain of sand, your head will spin. What a blessing that we have a good magnetic field and an excellent atmosphere that prevent us from dying!
People are exposed to this danger every day because radioactive radiation in space never runs out. It is from there that most of the radiation comes to us - from black holes and from clusters of stars. It is capable of killing with a large dose of radiation, and with a small dose it can turn us into mutants. However, we must also remember that evolution on Earth occurred thanks to such flows; radiation changed the structure of DNA to the state that we see today. If we go through this “medicine”, that is, if the radiation emitted by stars exceeds permissible levels, the processes will be irreversible. After all, if creatures mutate, they will not return to their original state; there is no reverse effect here. Therefore, we will never again see those living organisms that were present in the newborn life on Earth. Any organism tries to adapt to changes occurring in environment. Either he dies or he adapts. But there is no turning back.
ISS and solar flare
When the Sun sent us its greeting with a stream of charged particles, the ISS was just passing between the Earth and the star. The high-energy protons released during the explosion created a completely undesirable background radiation within the station. These particles penetrate through absolutely any spaceship. However, this radiation spared space technology, since the impact was powerful, but too short to disable it. However, the crew was hiding in a special shelter all this time, because the human body is much more vulnerable than modern technology. There was not just one flare, they came in a whole series, and it all started on September 4, 2017, in order to shake the cosmos with an extreme emission on September 6. Over the past twelve years, more than strong flow have not yet been observed on Earth. The cloud of plasma that was ejected by the Sun overtook the Earth much earlier than planned, which means that the speed and power of the flow exceeded the expected one and a half times. Accordingly, the impact on the Earth was much stronger than expected. The cloud was twelve hours ahead of all the calculations of our scientists, and accordingly more disturbed the planet’s magnetic field.
The power of the magnetic storm turned out to be four out of five possible, that is, ten times more than expected. In Canada, auroras were also observed even in mid-latitudes, as in Russia. A planetary magnetic storm occurred on Earth. You can imagine what was going on there in space! Radiation is the most significant danger of all existing there. Protection from it is needed immediately, as soon as the spacecraft leaves the upper atmosphere and leaves magnetic fields far below. Streams of uncharged and charged particles - radiation - constantly permeate space. The same conditions await us on any planet. solar system: There is no magnetic field or atmosphere on our planets.
Types of radiation
In space, ionizing radiation is considered the most dangerous. These are gamma radiation and X-rays from the Sun, these are particles flying after chromospheric solar flares, these are extragalactic, galactic and solar cosmic rays, solar wind, protons and electrons of radiation belts, alpha particles and neutrons. There is also non-ionizing radiation - this is ultraviolet and infrared radiation from the Sun, this is electromagnetic radiation and visible light. There is no great danger in them. We are protected by the atmosphere, and the astronaut is protected by a space suit and the skin of the ship.
Ionizing radiation causes irreparable harm. This is a harmful effect on all life processes that occur in the human body. When a high-energy particle or photon passes through a substance in its path, it forms a pair of charged particles called an ion as a result of interaction with this substance. This affects even nonliving matter, and living matter reacts most violently, since the organization of highly specialized cells requires renewal, and this process occurs dynamically as long as the organism is alive. And the higher the level of evolutionary development of the organism, the more irreversible the radiation damage becomes.
Radiation protection
Scientists are looking for such tools in a variety of areas modern science, including in pharmacology. So far, no drug has produced effective results, and people exposed to radiation continue to die. Experiments are carried out on animals both on earth and in space. The only thing that became clear was that any drug should be taken by a person before the start of radiation, and not after.
And if we take into account that all such drugs are toxic, then we can assume that the fight against the effects of radiation has not yet led to a single victory. Even if taken on time, pharmacological agents provide protection only against gamma radiation and X-rays, but do not protect against ionizing radiation from protons, alpha particles and fast neutrons.
One of the main negative biological factors in outer space, along with weightlessness, is radiation. But if the situation with weightlessness on various bodies of the Solar System (for example, on the Moon or Mars) will be better than on the ISS, then with radiation things are more complicated.
According to its origin, cosmic radiation is of two types. It consists of galactic cosmic rays (GCRs) and heavy positively charged protons emanating from the Sun. These two types of radiation interact with each other. During solar activity, the intensity of galactic rays decreases, and vice versa. Our planet is protected from the solar wind by a magnetic field. Despite this, some charged particles reach the atmosphere. The result is a phenomenon known as the aurora. High-energy GCRs are almost not delayed by the magnetosphere, but they do not reach the Earth's surface in dangerous quantities due to its dense atmosphere. The ISS orbit is above the dense layers of the atmosphere, but inside the Earth's radiation belts. Because of this, the level of cosmic radiation at the station is much higher than on Earth, but significantly lower than in outer space. According to their own protective properties The Earth's atmosphere is approximately equivalent to an 80 cm layer of lead.
The only reliable source of radiation dose that can be received during long-duration spaceflight and on the surface of Mars is the RAD instrument at the Mars Science Laboratory, better known as Curiosity. To understand how accurate the data it collects is, let's first look at the ISS.
In September 2013, the journal Science published an article on the results of the RAD tool. A comparison graph produced by NASA's Jet Propulsion Laboratory (an organization not associated with experiments conducted on the ISS, but working with the RAD instrument of the Curiosity rover) indicates that during a six-month stay on a near-Earth space station, a person receives a radiation dose of approximately equal to 80 mSv (millisievert). ). But the Oxford University publication from 2006 (ISBN 978-0-19-513725-5) states that an astronaut on the ISS receives an average of 1 mSv per day, i.e. the six-month dose should be 180 mSv. As a result, we see a huge scatter in estimates of the level of radiation in the long-studied low Earth orbit.
The main solar cycles have a period of 11 years, and since the GCR and solar wind are interconnected, for statistically reliable observations it is necessary to study radiation data at different parts of the solar cycle. Unfortunately, as stated above, all of the data we have on radiation in outer space was collected in the first eight months of 2012 by MSL on its way to Mars. Information about radiation on the surface of the planet was accumulated by him over the subsequent years. This does not mean that the data is incorrect. You just need to understand that they can only reflect the characteristics of a limited period of time.
The latest data from the RAD tool was published in 2014. According to scientists from NASA's Jet Propulsion Laboratory, during a six-month stay on the surface of Mars, a person will receive an average radiation dose of about 120 mSv. This figure is halfway between the lower and upper estimates of the radiation dose on the ISS. During the flight to Mars, if it also takes six months, the radiation dose will be 350 mSv, i.e. 2-4.5 times more than on the ISS. During its flight, MSL experienced five solar flares of moderate power. We do not know for sure what radiation dose astronauts will receive on the Moon, since no experiments were conducted that specifically studied cosmic radiation during the Apollo program. Its effects have been studied only in conjunction with the effects of other negative phenomena, such as the influence of lunar dust. However, it can be assumed that the dose will be higher than on Mars, since the Moon is not protected even by a weak atmosphere, but lower than in outer space, since a person on the Moon will be irradiated only “from above” and “from the sides” , but not from under your feet./
In conclusion, it can be noted that radiation is a problem that will definitely require a solution in the event of colonization of the Solar System. However, the widespread belief that the radiation environment outside the Earth's magnetosphere does not allow for long-term space flights is simply not true. To fly to Mars you will have to install protective covering either for the entire residential module of the space flight complex, or for a separate, especially protected “storm” compartment, in which astronauts can wait out proton showers. This does not mean that developers will have to use complex anti-radiation systems. To significantly reduce the level of radiation exposure, it is enough thermal insulation coating, which is used on spacecraft descent vehicles to protect against overheating during braking in the Earth's atmosphere.
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Space ribbon |
Near the Earth, its magnetic field continues to protect it - even if weakened and without the help of a multi-kilometer atmosphere. When flying near the poles, where the field is small, the astronauts sit in a specially protected room. But there is no satisfactory technical solution for radiation protection during a flight to Mars.
I decided to add to the original answer for two reasons:
- in one place it contains an incorrect statement and does not contain a correct one
- just for completeness (quotes)
1. In the comments, Suzanna criticized The answer is largely true.
The field weakens above the Earth's magnetic poles, as I stated. Yes, Suzanna is right that it is especially large at the POLES (imagine the lines of force: they gather precisely at the poles). But at a high altitude ABOVE THE POLES it is weaker than in other places - for the same reason (imagine the same lines of force: they went down - towards the poles, and at the top there are almost none left). The field seems to be subsiding.
But Suzanne is right that EMERCOM cosmonauts do not take shelter in a special room due to the polar regions: My memory failed me.
But still there is a place where special measures are being taken(I confused it with the polar regions). This - over a magnetic anomaly in the South Atlantic. There the magnetic field “sags” so much that the radiation belt and it is necessary to take special measures without any solar flares. I couldn’t quickly find a quote about special measures not related to solar activity, but I read about them somewhere.
And, of course, The flashes themselves are worth mentioning: They also take refuge from them in the most protected room, and do not wander around the entire station at this time.
All solar flares are carefully monitored and information about them is sent to the control center. During such periods, the cosmonauts stop working and take refuge in the most protected compartments of the station. Such protected segments are the ISS compartments next to the water tanks. Water retains secondary particles - neutrons, and the radiation dose is absorbed more efficiently.
2. Just quotes and additional information
Some quotes below mention dose in Sieverts (Sv). For orientation, some numbers and probable effects from the table in
0-0.25 Sv. No effect other than mild changes in blood
0.25-1 Sv. Radiation diseases from 5-10% of exposed people
7 Sv ~100% fatalities
The daily dose on the ISS is about 1 mSv (see below). Means, you can fly for about 200 days without much risk. It is also important over what period of time the same dose was collected: collected over a short time much more dangerous than what you earned for long term. An organism is not a passive object simply “accumulating” radiation defects: it also has “repair” mechanisms and they usually cope with gradually accrued small doses.
In the absence of the massive atmospheric layer that surrounds people on Earth, astronauts on the ISS are exposed to more intense radiation from constant streams of cosmic rays. Crew members receive a radiation dose of about 1 millisievert per day, which is approximately equivalent to the radiation exposure of a person on Earth in a year. This leads to an increased risk of developing malignant tumors in astronauts, as well as a weakened immune system.
As data collected by NASA and specialists from Russia and Austria show, astronauts on the ISS receive a daily dose of 1 millisievert. On Earth, such a dose of radiation cannot be obtained everywhere in a whole year.
This level, however, is still relatively tolerable. However, it must be borne in mind that near-Earth space stations are protected by the Earth's magnetic field.
Beyond its borders, radiation will increase many times, therefore, expeditions into deep space will be impossible.
Radiation in the residential buildings and laboratories of the ISS and Mir arose as a result of the bombardment of the aluminum cladding of the station by cosmic rays. Fast and heavy ions knocked out a fair amount of neutrons from the casing.
Currently, it is impossible to provide 100% radiation protection on spacecraft. More precisely, it is possible, but at the expense of a more than significant increase in mass, but this is precisely what is unacceptable
In addition to our atmosphere, the Earth’s magnetic field is a protection against radiation. The Earth's first radiation belt is located at an altitude of about 600-700 km. The station now flies at an altitude of about 400 km, which is significantly lower... Protection from radiation in space is (also - ed.) the hull of a ship or station. The thicker the case walls, the greater the protection. Of course, the walls cannot be infinitely thick, because there are weight restrictions.
The ionizing level, the background level of radiation on the International Space Station is higher than on Earth (about 200 times – ed.), which makes an astronaut more susceptible to ionizing radiation than representatives of traditionally radiation-hazardous industries, such as nuclear energy and x-ray diagnostics.
In addition to individual dosimeters for astronauts, the station also has a radiation monitoring system. ... One sensor is located in the crew cabins and one sensor in the small and small working compartment large diameter. The system operates autonomously 24 hours a day. ... Thus, the Earth has information about the current radiation situation at the station. The radiation monitoring system is capable of issuing a warning signal “Check the radiation!” If this had happened, then on the alarm system console we would have seen a banner light up with an accompanying sound signal. During the entire existence of the international space station, there have been no such cases.
In... the South Atlantic region... radiation belts “sag” above the Earth due to the existence of a magnetic anomaly deep under the Earth. Spaceships flying above the Earth seem to “strike” the radiation belts for a very short time... on orbits passing through the region of the anomaly. On other orbits, there are no radiation fluxes and do not cause trouble for space expedition participants.
The magnetic anomaly in the South Atlantic region is not the only radiation “scourge” for astronauts. Solar flares, sometimes generating very energetic particles..., can create great difficulties for astronaut flights. What dose of radiation an astronaut can receive in the event of solar particles arriving at Earth is largely a matter of chance. This value is determined mainly by two factors: the degree of distortion of the Earth's dipole magnetic field during magnetic storms and the parameters of the spacecraft's orbit during a solar event. ... The crew may be lucky if the orbits at the time of the SCR invasion do not pass through dangerous high-latitude areas.
One of the most powerful proton eruptions - a radiation storm of solar eruptions, which caused a radiation storm near the Earth, occurred quite recently - on January 20, 2005. A solar eruption of similar power occurred 16 years ago, in October 1989. Many protons with energies exceeding hundreds of MeV , reached the Earth's magnetosphere. By the way, such protons are able to overcome protection equivalent to about 11 centimeters of water. The astronaut's spacesuit is thinner. Biologists believe that if at this time the astronauts were outside the International Space Station, then, of course, the effects of radiation would affect the health of the astronauts. But they were inside her. The ISS's shielding is great enough to protect the crew from the adverse effects of radiation in many cases. This was the case during this event. As measurements using radiation dosimeters showed, the dose of radiation “captured” by the astronauts did not exceed the dose that a person receives during a regular X-ray examination. The ISS cosmonauts received 0.01 Gy or ~ 0.01 Sievert... True, such small doses are also due to the fact that, as was written earlier, the station was on “magnetically protected” orbits, which may not always happen.
Neil Armstrong (the first astronaut to walk on the moon) reported to Earth about his unusual sensations during the flight: sometimes he observed bright flashes in his eyes. Sometimes their frequency reached about a hundred per day... Scientists... came to the conclusion that galactic cosmic rays are responsible for this. It is these high-energy particles that penetrate the eyeball and cause Cherenkov glow when interacting with the substance that makes up the eye. As a result, the astronaut sees a bright flash. The most effective interaction with matter is not protons, of which cosmic rays contain more than all other particles, but heavy particles - carbon, oxygen, iron. These particles, having large mass, lose significantly more of their energy per unit of distance traveled than their lighter counterparts. They are responsible for the generation of Cherenkov glow and stimulation of the retina - the sensitive membrane of the eye.
During long-distance space flights, the role of galactic and solar cosmic rays as radiation-hazardous factors increases. It is estimated that during a flight to Mars it is GCRs that become the main radiation hazard. The flight to Mars lasts about 6 months, and the integral - total - radiation dose from the GCR and SCR during this period is several times higher than the radiation dose on the ISS for the same time. Therefore, the risk of radiation consequences associated with long-distance space missions increases significantly. Thus, over a year of flight to Mars, the absorbed dose associated with GCR will be 0.2-0.3 Sv (without protection). It can be compared with the dose from one of the most powerful flares of the last century - August 1972. During this event it was several times less: ~0.05 Sv.
The radiation hazard created by GCR can be assessed and predicted. A wealth of material has now been accumulated on the temporal variations of the GCR associated with the solar cycle. This made it possible to create a model on the basis of which it is possible to predict the GCR flux for any period of time specified in advance.
The situation with SCL is much more complicated. Solar flares occur randomly and it is not even obvious that powerful solar events occur in years necessarily close to maximum activity. At least experience recent years shows that they also occur during times of a quiet star.
Protons from solar flares pose a real threat to space crews on long-distance missions. Taking the August 1972 flare again as an example, it can be shown, by recalculating the fluxes of solar protons into the radiation dose, that 10 hours after the start of the event, it exceeded the lethal value for the crew spaceship, if he were outside the ship on Mars or, say, on the Moon.
Here it is appropriate to recall the American Apollo flights to the Moon in the late 60s and early 70s. In 1972, in August, there was a solar flare of the same power as in October 1989. Apollo 16 landed after its lunar journey in April 1972, and the next one, Apollo 17, launched in December. Lucky crew of Apollo 16? Absolutely yes. Calculations show that if the Apollo astronauts had been on the Moon in August 1972, they would have been exposed to a radiation dose of ~4 Sv. This is a lot to save. Unless... unless quickly returned to Earth for emergency treatment. Another option is to go to the Apollo lunar module cabin. Here the radiation dose would be reduced by 10 times. For comparison, let's say that the protection of the ISS is 3 times thicker than the Apollo lunar module.
At the altitudes of orbital stations (~400 km), radiation doses exceed the values observed on the Earth's surface by ~200 times! Mainly due to particles from radiation belts.
It is known that some routes of intercontinental aircraft pass near the northern polar region. This area is least protected from the invasion of energetic particles and therefore during solar flares the danger of radiation exposure to the crew and passengers increases. Solar flares increase radiation doses at aircraft flight altitudes by 20-30 times.
IN Lately Some airline crews are informed that the solar particle invasion is about to begin. One of the recent powerful solar eruptions, which occurred in November 2003, forced the Delta crew on the Chicago-Hong Kong flight to turn off the path: to fly to their destination on a lower latitude route.
The Earth is protected from cosmic radiation by the atmosphere and magnetic field. In orbit, the background radiation is hundreds of times greater than on the Earth's surface. Every day, an astronaut receives a radiation dose of 0.3-0.8 millisieverts - approximately five times more than a chest x-ray. When working in outer space, the exposure to radiation is even higher. And during moments of powerful solar flares, you can reach the 50-day norm in one day at the station. God forbid you work overboard at such a time - in one exit you can choose the dose allowed for your entire career, which is 1000 millisieverts. Under normal conditions, it would have lasted for four years - no one has flown that long before. Moreover, the damage to health from such a single exposure will be significantly higher than from exposure extended over years.
Yet low Earth orbits are still relatively safe. The Earth's magnetic field traps charged particles from the solar wind, forming radiation belts. They are shaped like a wide donut, surrounding the Earth at the equator at an altitude of 1,000 to 50,000 kilometers. The maximum particle density is achieved at altitudes of about 4,000 and 16,000 kilometers. Any prolonged delay of a ship in the radiation belts poses a serious threat to the life of the crew. Crossing them on the way to the Moon, American astronauts risked receiving a dose of 10-20 millisieverts in a few hours - the same as in a month of work in orbit.
In interplanetary flights, the issue of crew radiation protection is even more acute. The Earth screens half of the hard cosmic rays, and its magnetosphere almost completely blocks the flow of solar wind. In outer space, without additional protective measures, radiation exposure will increase by an order of magnitude. The idea of deflecting cosmic particles with strong magnetic fields, however, in practice, nothing except shielding has yet been worked out. Cosmic radiation particles are well absorbed by rocket fuel, which suggests using full tanks as protection against dangerous radiation.
The magnetic field at the poles is not small, but on the contrary, large. It’s just directed there almost radially towards the Earth, which leads to the fact that solar wind particles captured by magnetic fields in the radiation belts, when certain conditions move (precipitate) towards the Earth at the poles, causing auroras. This does not pose a danger to astronauts since the ISS trajectory passes closer to the equatorial zone. The danger is posed by strong solar flares of class M and X with coronal ejections of matter (mainly protons) directed towards the Earth. It is in this case that astronauts use additional radiation protection measures.
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QUOTE: "... The most effective interaction with matter is not protons, of which cosmic rays contain more than all other particles, but heavy particles - carbon, oxygen, iron...."
Please explain to the ignorant - where did the particles of carbon, oxygen, iron come from in the solar wind (cosmic rays, as you write) and how can they get into the substance of which the eye is made - through a spacesuit?
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Let me explain... Sunlight is photons(including gamma rays and x-rays, which are penetrating radiation).
Is there some more sunny wind. Particles. For example, electrons, ions, atomic nuclei flying from and to the Sun. There are few heavy nuclei (heavier than helium) there, because there are few of them in the Sun itself. But there are a lot of alpha particles (helium nuclei). And, in principle, any core that is lighter than an iron one can arrive (the only question is the number of those arriving). Synthesis of iron on the Sun (especially outside it) does not go further than iron. Therefore, only iron and something lighter (the same carbon, for example) can come from the Sun.
Cosmic rays in the narrow sense- This especially high-speed charged particles(and not charged, however, either), arriving from outside the solar system (mostly). And also - penetrating radiation from there(sometimes it is considered separately, without being included among the “rays”).
Among other particles, cosmic rays contain the nuclei of any atoms(V different quantities, Certainly). Anyhow heavy nuclei, once in a substance, ionize everything in their path(and also - aside: there is secondary ionization - already by what is knocked out along the road). And if they have high speed (and kinetic energy), then the nuclei will be engaged in this activity (flight through matter and its ionization) for a long time and will not stop soon. Respectively, will fly through anything and will not deviate from the path- until they spend almost all kinetic energy. Even if they bump directly into another cannonball (and this happens rarely), they can simply throw it aside, almost without changing the direction of their movement. Or not to the side, but will fly further in more or less one direction.
Imagine a car that full speed ahead crashed into another. Will he stop? And imagine that its speed is many thousands of kilometers per hour (even better - per second!), and its strength allows it to withstand any blow. This is the core from space.
Cosmic rays in a broad sense- these are cosmic rays in a narrow way, plus the solar wind and penetrating radiation from the Sun. (Well, or without penetrating radiation, if it is considered separately).
The solar wind is a stream of ionized particles (mainly helium-hydrogen plasma) flowing from the solar corona at a speed of 300-1200 km/s into the surrounding outer space. It is one of the main components of the interplanetary medium.
Many natural phenomena are associated with the solar wind, including space weather phenomena such as magnetic storms and auroras.
The concepts of “solar wind” (a stream of ionized particles that travels from the Sun to the Earth in 2-3 days) and “sunlight” (a stream of photons that travels from the Sun to the Earth in an average of 8 minutes 17 seconds) should not be confused.
Due to the solar wind, the Sun loses about one million tons of matter every second. The solar wind consists primarily of electrons, protons, and helium nuclei (alpha particles); the nuclei of other elements and non-ionized particles (electrically neutral) are contained in very small quantities.
Although the solar wind comes from the outer layer of the Sun, it does not reflect the composition of the elements in this layer, since as a result of differentiation processes the abundance of some elements increases and some decreases (FIP effect).
Cosmic rays are elementary particles and atomic nuclei moving with high energies in outer space[
Classification according to the origin of cosmic rays:
- outside our Galaxy
- in the Galaxy
- in the sun
- in interplanetary space
Extragalactic and galactic rays are usually called primary. Secondary flows of particles passing and transforming in the Earth’s atmosphere are usually called secondary.
Cosmic rays are a component of natural radiation (background radiation) on the Earth's surface and in the atmosphere.
The energy spectrum of cosmic rays consists of 43% of the energy of protons, another 23% of the energy of helium (alpha particles) and 34% of the energy transferred by other particles.
By particle number, cosmic rays are 92% protons, 6% helium nuclei, about 1% heavier elements, and about 1% electrons.
Traditionally, particles observed in cosmic rays are divided into the following groups... respectively, protons, alpha particles, light, medium, heavy and superheavy... Feature chemical composition primary cosmic radiation is the anomalously high (several thousand times) content of group L nuclei (lithium, beryllium, boron) compared to the composition of stars and interstellar gas. This phenomenon is explained by the fact that the mechanism of generation of cosmic particles primarily accelerates heavy nuclei, which, when interacting with protons of the interstellar medium, decay into lighter nuclei.
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