Mankind treats the cosmos as something unknown and mysterious. Space is a void that exists between celestial bodies. The atmospheres of solid and gaseous celestial bodies (and planets) do not have a fixed upper limit, but gradually become thinner as the distance to the celestial body increases. At a certain height, this is called the beginning of space. What is the temperature in space, and other information will be discussed in this article.

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General concept

In outer space there is high vacuum with low particle density. There is no air in space. What is space made of? This is not empty space, it contains:

• gases;
• space dust;
• elementary particles (neutrinos, cosmic rays);
• electric, magnetic and gravitational fields;
• also electromagnetic waves (photons).

An absolute vacuum, or almost complete vacuum, makes space transparent, and makes it possible to observe extremely distant objects such as other galaxies. But the haze of interstellar matter can also seriously obscure the idea of ​​them.

Important! The concept of space should not be identified with the Universe, which includes all space objects, even stars and planets.

Travel or transport in or through outer space is called space travel.

Where does space begin

Can't say for sure what height does it start space. The International Aviation Federation defines the edge of space at an altitude of 100 km above sea level, the Karman line.

It is necessary that the aircraft move at the first cosmic speed, then the lifting force will be achieved. The US Air Force defined an altitude of 50 miles (about 80 km) as the beginning of space.

Both heights are proposed as limits for the upper layers. On the international level there is no definition of the edge of space.

The Venus Pocket line is located at about 250 km altitude, Mars - about 80 km. For celestial bodies that have little or no atmosphere, such as Mercury, Earth's moon, or an asteroid, space begins right on the surface body.

When the spacecraft re-enters the atmosphere, the height of the atmosphere is determined to calculate the trajectory so that its influence to the re-entry point is minimal. Typically, the re-entry level is equal to or higher than the Pockets line. NASA uses a value of 400,000 feet (about 122 km).

What is the pressure and temperature in space

Absolute vacuum unattainable even in space. Since there are several hydrogen atoms for a certain volume. At the same time, the magnitude of the cosmic vacuum is not enough for a person to burst, like a balloon that has been pumped over. This will not happen for the simple reason that our body is strong enough to hold its shape, but it still will not save the body from death.

And it's not about durability. And not even in the blood, although it contains about 50% water, it is in a closed system under pressure. Maximum - saliva, tears, and liquids that wet the alveoli in the lungs will boil. Roughly speaking, a person will die from suffocation. Even at relatively low altitudes in the atmosphere, conditions are hostile to the human body.

Scientists are arguing: complete vacuum or not in space, but still tend to believe that the full value is unattainable due to hydrogen molecules.

The altitude at which atmospheric pressure corresponds to the vapor pressure of water at human body temperature, ncalled the Armstrong line. It is located at an altitude of about 19.14 km. In 1966, an astronaut tested a spacesuit and was subjected to decompression at an altitude of 36,500 meters. In 14 seconds, he turned off, but did not explode, but survived.

Maximum and minimum values

The initial temperature in outer space, as set by the background radiation from the Big Bang, is 2.73 kelvin (K), which is equal to -270.45 °C.

This is the coldest temperature in space. The space itself has no temperature, but only the matter that is in it, and the acting radiation. To be more precise, then absolute zero is a temperature of -273.15 °C. But within the framework of such a science as thermodynamics, this is impossible.

Because of the radiation in space, the temperature is kept at 2.7 K. The temperature of the vacuum is measured in units of the kinetic activity of the gas, just like on Earth. The radiation filling the vacuum has a different temperature than the kinetic temperature of the gas, meaning that the gas and radiation are not in thermodynamic equilibrium.

Absolute zero is what it is. lowest temperature but in space.

Matter locally distributed in space can have very high temperatures. The Earth's atmosphere at high altitude reaches a temperature of about 1400 K. Intergalactic plasma gas with a density of less than one hydrogen atom per cubic meter can reach temperatures of several million K. The high temperature in outer space is due to the speed of particles. However, a general thermometer will read temperatures near absolute zero because the particle density is too low to allow measurable heat transfer.

The entire observable universe is filled with photons that were created during the Big Bang. It is known as the cosmic microwave background radiation. There is a large number of neutrinos, called the cosmic neutrino background. Current black body temperature background radiation is about 3-4 K. The temperature of gas in outer space is always at least the background radiation temperature, but can be much higher. For example, the corona has temperatures in excess of 1.2-2.6 million K.

Human body

There is another misconception related to temperature, which touches the human body. As you know, our body on average consists of 70% water. The heat that it releases in a vacuum has nowhere to go, therefore, heat exchange in space does not occur and a person overheats.

But before he does it, he will die from decompression. For this reason, one of the problems that astronauts face is heat. And the skin of the ship, which is in orbit under the open sun, can become very hot. The temperature in space in Celsius can be 260 °C on a metal surface.

Solids in near-Earth or interplanetary space experience large radiant heat on the side facing the sun. On the sunny side, or when bodies are in the Earth's shadow, they experience extreme cold because they release their thermal energy into space.

For example, an astronaut's spacewalk suit on the International Space Station would have a temperature of about 100°C on the side facing the sun.

On the night side of the Earth, solar radiation is obscured, and the earth's weak infrared radiation causes the suit to cool down. Its temperature in space in Celsius will be about -100 °C.

Heat exchange

Important! Heat transfer in space is possible by one single type - radiation.

This is a tricky process and its principle is used to cool the surfaces of the apparatus. The surface absorbs radiant energy that falls on it, and at the same time radiates energy into space, which is equal to the sum of the absorbed and supplied from the inside.

It is not known exactly what the pressure in space could be, but it is very small.

In most galaxies, observations show that 90% of the mass is in an unknown form called dark matter, which interacts with other matter through gravitational but not electromagnetic forces.

Much of the mass energy in the observable universe is the poorly understood vacuum energy of space, which astronomers refer to as dark energy. intergalactic space occupies most of the volume of the universe, but even galaxies and star systems are composed almost entirely of empty space.

Research

Humans started during the 20th century with the advent of high-altitude ballooning and then manned rocket launches.

Earth orbit was first achieved by Yuri Gagarin of the Soviet Union in 1961, and unmanned spacecraft have since made their way to all known.

Due to the high cost of spaceflight, manned spaceflight has been limited to low Earth orbit and the Moon.

Outer space is a difficult environment for human study due to the double hazards: vacuum and radiation. Microgravity also negatively affects human physiology, which causes both muscle atrophy and bone loss. In addition to these health and environmental concerns, the economic cost of putting objects, including humans, into space is very high.

How cold is it in space? Could the temperature be even lower?

Temperatures in different parts of the universe

Conclusion

Since light has a finite speed, the dimensions of the directly observable universe are limited. This leaves open the question of whether the universe is finite or infinite. Space continues to be a mystery to man full of phenomena. Modern science still cannot answer many questions. But what temperature in space has already been found out, and what pressure in space can be measured over time.

The latest data, obtained through a thorough study and generalization of a large amount of information over almost two years, allowed Canadian scientists in the first half of April to declare that space begins at an altitude of 118 km ...

Andrey Kislyakov, for RIA Novosti.

It would seem that it is not so significant where the "Earth" ends and space begins. Meanwhile, disputes over the meaning of the height, beyond which boundless outer space already stretches, have not subsided for almost a century. The latest data, obtained through a thorough study and generalization of a large amount of information for almost two years, allowed Canadian scientists in the first half of April to declare that space begins at an altitude of 118 km. From the point of view of the impact of cosmic energy on the Earth, this number is very important for climatologists and geophysicists.

On the other hand, it is unlikely that it will be possible soon to finally end this dispute by establishing a single border that suits everyone by the whole world. The fact is that there are several parameters that are considered fundamental for the corresponding assessment.

A bit of history. The fact that hard cosmic radiation acts outside the earth's atmosphere has long been known. However, it was not possible to clearly define the boundaries of the atmosphere, measure the strength of electromagnetic flows and obtain their characteristics before the launch of artificial Earth satellites. Meanwhile, the main space task of both the USSR and the United States in the mid-1950s was the preparation of a manned flight. This, in turn, required a clear knowledge of the conditions just outside the earth's atmosphere.

Already on the second Soviet satellite, launched in November 1957, there were sensors for measuring solar ultraviolet, X-ray and other types of cosmic radiation. Fundamentally important for the successful implementation of manned flights was the discovery in 1958 of two radiation belts around the Earth.

But back to the 118 km established by Canadian scientists from the University of Calgary. And why, in fact, such a height? After all, the so-called "Karman Line", unofficially recognized as the boundary between the atmosphere and space, "passes" along the 100-kilometer mark. It is there that the air density is already so low that the aircraft must move at the first space velocity (about 7.9 km / s) to prevent falling to Earth. But in this case, he no longer needs aerodynamic surfaces (wing, stabilizers). Based on this, the World Aeronautics Association has adopted an altitude of 100 km as the watershed between aeronautics and astronautics.

But the degree of rarefaction of the atmosphere is far from the only parameter that determines the boundary of space. Moreover, the “terrestrial air” does not end at an altitude of 100 km. And how, say, does the state of a substance change with increasing height? Maybe this is the main thing that determines the beginning of the cosmos? Americans, in turn, consider anyone who has been at an altitude of 80 km, a true astronaut.

In Canada, they decided to identify the value of a parameter that seems to matter for our entire planet. They decided to find out at what height the influence of atmospheric winds ends and the influence of cosmic particle flows begins.

For this purpose, a special device STII (Super - Thermal Ion Imager) was developed in Canada, which was launched into orbit from a cosmodrome in Alaska two years ago. With its help, it was found that the boundary between the atmosphere and space is located at an altitude of 118 kilometers above sea level.

At the same time, data collection lasted only five minutes, while the satellite carrying it rose to its assigned altitude of 200 km. This is the only way to collect information, since this mark is too high for stratospheric probes and too low for satellite research. For the first time, the study took into account all the components, including the movement of air in the uppermost layers of the atmosphere.

Instruments like the STII will be used to continue exploration of the border regions of space and the atmosphere as a payload on satellites of the European Space Agency, the active life of which will be four years. This is important because Continued research on the border regions will make it possible to learn many new facts about the impact of cosmic radiation on the Earth's climate, about the impact that ion energy has on our environment.

The change in the intensity of solar radiation, directly related to the appearance of spots on our star, somehow affects the temperature of the atmosphere, and the followers of the STII apparatus can be used to detect this influence. Already today, 12 different analyzing devices have been developed in Calgary, designed to study various parameters of the near space.

But it is not necessary to say that the beginning of space was limited to 118 km. Indeed, for their part, those who consider a height of 21 million kilometers to be real space are right! It is there that the influence of the Earth's gravitational field practically disappears. What awaits researchers at such a cosmic depth? After all, we did not climb further than the Moon (384,000 km).

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How far from Earth does space begin?

What is space, probably, many people know. But, few people thought about where the cosmos actually begins. Indeed, at what height from the Earth can we say that the object is already (or still) in space?

This question, it must be said, is not idle. Many people remember the tragic launch of the American shuttle Challenger in 1985, when after a few minutes of flight the reusable spacecraft exploded. After this accident, the question arose - should the dead crew members be considered astronauts? The dead were not included in the number of astronauts, although the explosion occurred at a very high altitude.

There is no consensus among scientists at what height space begins. For the "reference point" various options are offered. Thus, Canadian experts propose to consider the height of 118 kilometers as the beginning of space, since this is the “standard” height from which climatologists and geophysicists “look” at our planet. Some scientists suggest relying on gravity indicators. In this case, space will begin at a distance of about 21 million kilometers, this is where the earth's gravity completely disappears. But, in this case, all current cosmonauts and astronauts will not be such. Then only flights beyond the orbit of the Moon will remain space.

NASA experts believe that space begins at a height of 122 kilometers, it is this mark adopted by the MCC when the onboard engines of the descent vehicle are turned off and the aerodynamic descent from orbit begins. However, Soviet cosmonauts also perform ballistic entry into the Earth's atmosphere from other heights.

If we take the "burning" of meteorites falling into the earth's atmosphere as the beginning of space, then this will be a distance of 80 km from the Earth.

As you can see, there are many options. In order to somehow "legitimize" the initial boundary of space, scientists compromised and proposed to consider the space altitude at which planes can no longer fly due to the very low air density - 100 kilometers from the Earth's surface.

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Distances in space. Stars and objects closest to us

Everyone has ever traveled, spending a specific time on overcoming the path. How endless the road seemed when it was measured in days. From the capital of Russia to the Far East - seven days by train! And if on this transport to overcome distances in space? It takes only 20 million years to get to Alpha Centauri by train. No, it's better by plane - it's five times faster. And this is up to the star that is nearby. Of course, nearby - this is by stellar standards.

Distance to the Sun

Aristarchus of Samos Aristarchus of Samos Astronomer, mathematician and philosopher, lived in the III century BC. e. He was the first to guess that the earth revolves around the sun and proposed a scientific method for determining the distances to it. 200 years before our era, he tried to determine the distance to the Sun. But his calculations were not very correct - he was wrong by 20 times. More accurate values ​​were obtained by the Cassini spacecraft in 1672. The positions of Mars during its opposition were measured from two different points on the Earth. The calculated distance to the Sun turned out to be 140 million km. In the middle of the 20th century, with the help of Venus radar, the true parameters of the distances to the planets and the Sun were found out.

Now we know that the distance from the earth to the Sun is 149,597,870,691 meters. This value is called the astronomical unit, and it is the foundation for determining cosmic distances using the stellar parallax method.

Long-term observations have also shown that the Earth moves away from the Sun by about 15 meters in 100 years.

Distances to nearest objects

We don't think much about distance when we watch live broadcasts from far corners of the globe. The TV signal comes to us almost instantly. Even from our satellite, the Moon, radio waves reach the Earth in a second and a tail. But it is worth talking about objects more distant, and surprise immediately comes. Does it really take 8.3 minutes for light to travel to such a close Sun, and 5.5 hours to icy Pluto? And this, flying almost 300,000 km in a second! And in order to get to the same Alpha in the constellation Centaurus, a beam of light will take 4.25 years.

Even for near space, our usual units of measurement are not quite suitable. Of course, you can measure in kilometers, but then the numbers will not cause respect, but some fear of their size. For our solar system, it is customary to measure in astronomical units.

Now space distances to planets and other objects of near space will not look so scary. From our star to Mercury is only 0.387 AU, and to Jupiter - 5.203 AU. Even to the most distant planet - Pluto - only 39.518 AU.

The distance to the Moon is determined to the nearest kilometer. This was done by placing corner reflectors on its surface and using the laser location method. The average value of the distance to the Moon turned out to be 384,403 km. But the solar system extends much beyond the orbit of the last planet. To the border of the system as much as 150,000 AU. e. Even these units begin to be expressed in grandiose quantities. Other measurement standards are appropriate here, because the distances in space and the size of our Universe are beyond the boundaries of reasonable ideas.

Medium space

There is nothing faster than light in nature (until such sources are known), therefore, it was its speed that was taken as the basis. For objects closest to our planetary system, and for those far from it, the path traveled by light in one year is taken as a unit. Light flies to the edge of the solar system for about two years, and to the nearest star in Centaurus 4.25 sv. of the year. The well-known Polar Star is located at a distance of 460 St. from us. years.

Each of us dreamed of going to the past or the future. Traveling into the past is entirely possible. You just need to look into the night starry sky - this is the past, distant and infinitely distant.

We observe all space objects in their distant past, and the farther the observed object, the farther into the past we look. While the light flies from a distant star to us, so much time passes that perhaps at the moment this star no longer exists!

The brightest star in our sky - Sirius - will go out for us only 9 years after his death, and the red giant Betelgeuse - only after 650 years.

Our galaxy is 100,000 light across. years, and a thickness of about 1,000 sv. years. It is incredibly difficult to imagine such distances, and it is almost impossible to estimate them. Our Earth, together with its luminary and other objects of the solar system, revolves around the center of the galaxy in 225 million years, and makes one revolution in 150,000 light years. years.

deep space

Distances in space to distant objects are measured using the parallax (displacement) method. Another unit of measurement emerged from it - the parsec. Parsec (pc) - from parallactic second This is the distance from which the radius of the earth's orbit is observed at an angle of 1 ″ .. The value of one parsec was 3.26 sv. year or 206 265 a. e. Accordingly, there are both thousands of parsecs (Kpc) and millions (Mpc). And the farthest objects in the universe will be expressed in terms of distances of a billion parsecs (Gpc). The parallax method can be used to determine the distances to objects that are no further than 100 pc, b about Larger distances will have very significant measurement errors. The photometric method is used to study distant cosmic bodies. This method is based on the properties of Cepheids - variable stars.

Each Cepheid has its own luminosity, the intensity and nature of which can be used to estimate the distance of an object located nearby.

Also, supernovae, nebulae, or very large stars of the supergiant and giant classes are used to determine brightness distances. Using this method, it is realistic to calculate the cosmic distances to objects located no further than 1000 Mpc. For example, to the galaxies closest to the Milky Way - the Large and Small Magellanic Clouds, it turns out 46 and 55 Kpc, respectively. And the nearest galaxy, the Andromeda Nebula, will be at a distance of 660 Kpc. The group of galaxies in the constellation Ursa Major is 2.64 Mpc away from us. And the size of the visible universe is 46 billion light years, or 14 Gpc!

Measurements from space

To improve the accuracy of measurements, the Hipparchus satellite was launched in 1989. The task of the satellite was to determine the parallaxes of more than 100 thousand stars with millisecond accuracy. As a result of observations, the distances for 118,218 stars were calculated. They included more than 200 Cepheids. For some objects, previously known parameters have changed. For example, the Pleiades open star cluster approached - instead of 135 pc of the previous distance, only 118 pc were obtained.

light-science.ru

Distances in space

The distance between the Earth and the Moon is huge, but it seems tiny compared to the scale of space.

Outer spaces, as you know, are quite large-scale, and therefore astronomers do not use the metric system that is familiar to us to measure them. In the case of the distance to the Moon (384,000 km), kilometers can still be applied, but if we express the distance to Pluto in these units, we get 4,250,000,000 km, which is already less convenient for recording and calculations. For this reason, astronomers use other distance units, which you can read about below.

astronomical unit

The smallest of these units is the astronomical unit (AU). Historically, one astronomical unit is equal to the radius of the Earth's orbit around the Sun, otherwise - the average distance from the surface of our planet to the Sun. This method of measurement was most suitable for studying the structure of the solar system in the 17th century. Its exact value is 149,597,870,700 meters. Today, the astronomical unit is used in calculations with relatively short lengths. That is, when studying distances within the solar system or other planetary systems.

Light year

A slightly larger unit of length in astronomy is the light year. It is equal to the distance that light travels in vacuum in one Earth, Julian year. The zero influence of gravitational forces on its trajectory is also implied. One light year is about 9,460,730,472,580 km or 63,241 AU. This unit of length is used only in popular science literature for the reason that the light year allows the reader to get a rough idea of ​​distances on a galactic scale. However, due to its inaccuracy and inconvenience, the light year is practically not used in scientific work.

Related materials

Parsec

The most practical and convenient for astronomical calculations is such a unit of distance measurement as a parsec. To understand its physical meaning, one should consider such a phenomenon as parallax. Its essence lies in the fact that when the observer moves relative to two bodies distant from each other, the apparent distance between these bodies also changes. In the case of stars, the following happens. When the Earth moves in its orbit around the Sun, the visual position of the stars close to us changes somewhat, while the distant stars, acting as a background, remain in the same places. The change in the position of a star when the Earth shifts by one radius of its orbit is called the annual parallax, which is measured in arc seconds.

Then one parsec is equal to the distance to the star, the annual parallax of which is equal to one arc second - the unit of angle in astronomy. Hence the name "parsec", combined from two words: "parallax" and "second". The exact value of a parsec is 3.0856776 10 16 meters or 3.2616 light years. 1 parsec is equal to approximately 206,264.8 AU. e.

Method of laser location and radar

These two modern methods serve to determine the exact distance to an object within the solar system. It is produced in the following way. With the help of a powerful radio transmitter, a directed radio signal is sent towards the object of observation. After that, the body beats off the received signal and returns to Earth. The time it takes the signal to complete the path determines the distance to the object. Radar accuracy is only a few kilometers. In the case of laser location, instead of a radio signal, a light beam is sent by the laser, which allows you to determine the distance to the object by similar calculations. The accuracy of laser location is achieved down to fractions of a centimeter.

Telescope TG-1 of the laser locator LE-1, Sary-Shagan test site

Trigonometric parallax method

The simplest method for measuring the distance to distant space objects is the trigonometric parallax method. It is based on school geometry and consists of the following. Let's draw a segment (basis) between two points on the earth's surface. Let's select an object in the sky, the distance to which we intend to measure, and define it as the top of the resulting triangle. Next, we measure the angles between the basis and the straight lines drawn from the selected points to the body in the sky. And knowing the side and two corners of a triangle adjacent to it, you can find all its other elements.

Trigonometric parallax

The value of the selected basis determines the accuracy of the measurement. After all, if the star is located at a very large distance from us, then the measured angles will be almost perpendicular to the basis and the error in their measurement can significantly affect the accuracy of the calculated distance to the object. Therefore, the most remote points on Earth should be chosen as a basis. Initially, the radius of the Earth acted as a basis. That is, the observers were located at different points of the globe and measured the mentioned angles, and the angle located opposite the basis was called the horizontal parallax. However, later, as a basis, they began to take a greater distance - the average radius of the Earth's orbit (astronomical unit), which made it possible to measure the distance to more distant objects. In this case, the angle opposite the basis is called the annual parallax.

This method is not very practical for studies from the Earth, for the reason that due to the interference of the Earth's atmosphere, it is not possible to determine the annual parallax of objects located more than 100 parsecs away.

However, in 1989, the Hipparcos Space Telescope was launched by the European Space Agency, which made it possible to identify stars at a distance of up to 1000 parsecs. As a result of the data obtained, scientists were able to compile a three-dimensional map of the distribution of these stars around the Sun. In 2013, ESA launched the next satellite, Gaia, which is 100 times more accurate, allowing all the stars in the Milky Way to be observed. If human eyes had the accuracy of the Gaia telescope, then we would be able to see the diameter of a human hair from a distance of 2,000 km.

Method of standard candles

To determine the distances to stars in other galaxies and the distances to these galaxies themselves, the standard candle method is used. As you know, the farther the light source is from the observer, the dimmer it seems to the observer. Those. the illumination of a light bulb at a distance of 2 m will be 4 times less than at a distance of 1 meter. This is the principle by which the distance to objects is measured using the standard candle method. Thus, drawing an analogy between a light bulb and a star, one can compare the distances to light sources with known powers.

The scale of the universe explored by existing methods is impressive. View infographic in full size.

The standard candles in astronomy are objects whose luminosity (analogous to the power of the source) is known. It can be any kind of star. To determine its luminosity, astronomers measure the surface temperature based on the frequency of its electromagnetic radiation. Then, knowing the temperature, which makes it possible to determine the spectral type of a star, its luminosity is determined using the Hertzsprung-Russell diagram. Then, having the values ​​of luminosity and measuring the brightness (apparent value) of the star, you can calculate the distance to it. Such a standard candle allows you to get a general idea of ​​​​the distance to the galaxy in which it is located.

However, this method is quite laborious and not very accurate. Therefore, it is more convenient for astronomers to use cosmic bodies with unique features as standard candles, for which the luminosity is known initially.

Unique standard candles

Cepheid PTC Puppis

Cepheids are the most commonly used standard candles, which are variable pulsating stars. By studying the physical features of these objects, astronomers have learned that Cepheids have an additional characteristic - a pulsation period that can be easily measured and which corresponds to a certain luminosity.

As a result of observations, scientists are able to measure the brightness and period of pulsation of such variable stars, and hence the luminosity, which makes it possible to calculate the distance to them. Finding a Cepheid in another galaxy makes it possible to relatively accurately and simply determine the distance to the galaxy itself. Therefore, this type of star is often referred to as the "beacons of the universe."

Despite the fact that the Cepheid method is most accurate at distances up to 10,000,000 pc, its error can reach 30%. To improve accuracy, as many Cepheids as possible in one galaxy will be required, but even in this case, the error is reduced to at least 10%. The reason for this is the inaccuracy of the period-luminosity dependence.

Cepheids are the "beacons of the universe".

In addition to Cepheids, other variable stars with known period-luminosity relationships can also be used as standard candles, as well as supernovae with known luminosity for the greatest distances. Close in accuracy to the Cepheid method is the method with red giants as standard candles. As it turned out, the brightest red giants have an absolute magnitude in a fairly narrow range, which allows you to calculate the luminosity.

Distances in numbers

Distances in the solar system:

• 1 a.u. from the Earth to the Sun = 500 sv. seconds or 8.3 sv. minutes
• 30 a. e. from the Sun to Neptune = 4.15 light hours
• 132 a.u. from the Sun - this is the distance to the Voyager 1 spacecraft, was noted on July 28, 2015. This object is the most remote of those that have been constructed by man.

Distances in the Milky Way and beyond:

• 1.3 parsecs (268144 AU or 4.24 light years) from the Sun to Proxima Centauri, the closest star to us
• 8,000 parsecs (26 thousand light years) - the distance from the Sun to the center of the Milky Way
• 30,000 parsecs (97 thousand light years) - the approximate diameter of the Milky Way
• 770,000 parsecs (2.5 million light years) - the distance to the nearest large galaxy - the Andromeda nebula
• 300,000,000 pc - scales on which the Universe is almost homogeneous
• 4,000,000,000 pc (4 Gigaparsec) is the edge of the observable universe. This is the distance traveled by the light recorded on Earth. Today, the objects that emitted it, taking into account the expansion of the Universe, are located at a distance of 14 gigaparsecs (45.6 billion light years).

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how many kilometers to space to shuttle orbit

Debris in Earth orbit threatens the continuation of space travel

Tens of millions of artificial objects, about 13 thousand of which are large objects, orbit the Earth, posing a threat to further space flights. This is stated in the quarterly report of the NASA department responsible for monitoring near-Earth space.

According to the document, there are 12,851 large objects of artificial origin in orbit, of which 3,190 operating and failed satellites and 9,661 rocket stages and other space debris. The number of space debris particles ranging in size from 1 to 10 cm is over 200 thousand , according to Interfax.

And the number of particles less than 1 cm, experts suggest, exceeds tens of millions. Basically, space debris is concentrated at altitudes from 850 to 1500 km above the Earth's surface, but there is also a lot of it at the flight altitudes of spacecraft and the International Space Station (ISS).

In August, the Mission Control Center conducted a maneuver to avoid the ISS from a collision with a piece of space debris, and in October it postponed the correction of the station's orbit due to the danger of a new collision.

Earlier, NASA also reported that the flight of the American shuttle Atlantis to repair the Hubble telescope could pose a danger to the crew. The telescope is in orbit about 600 km above the Earth, that is, almost twice as high as the ISS orbit, so the probability of meeting with space debris, according to experts, almost doubles.

If space debris located at altitudes below 600 km enters the atmosphere for several years and burns up in it, then debris located at altitudes of 800 km takes decades, and artificial objects at altitudes of thousands of kilometers and above hundreds of years. , according to NASA.

According to NASA spokesman Nicholson Johnson, who spoke in April at a meeting in Moscow of the 26th session of the Inter-Agency Space Debris Coordination Committee, there are two methods to combat the appearance of new space debris in orbit. One of them is the removal of fragments of launch vehicles from orbit using the fuel remaining on their board. The second method is the removal of spacecraft that have served their time into disposal orbits. According to experts, the lifetime of such devices at these points of the orbit can be 200 years or more.

Out of 13 thousand artificial objects, Russia and other CIS countries own 4528 fragments of space debris (1375 satellites and 3153 stages of rockets and other space debris).

The United States has 4259 objects (1096 satellites and 3163 stages of rockets and other elements of space technology).

The Chinese contribution to space debris is almost half that. The total number of objects listed for the PRC is 2774 (70 satellites and 2704 fragments of space technology and stages of launch vehicles).

France owns 376 artificial objects in Earth orbit, Japan - 175, India - 144, the European Space Agency - 74. Other countries - 521 objects of artificial origin.

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how many kilometers from earth to space?

from the earth to the uppermost shell of the earth 50,000 km
to the moon 80,000 km

Space is considered to begin at the level of 100 km. from the earth.

The conditional boundary of space is 100 km.
Conditional because there are no stretched ropes with signs: “Attention! Then space begins, flying on airplanes is strictly prohibited! “We just agreed.

In fact, there are a number of reasons why it was agreed that way, but they, too, are rather arbitrary.

From a height of 30 km already begins

first understand the terms, and then ask questions. space is the whole material world and the distance to it is 0 km. Outer space is a relatively empty part of space outside the atmospheres of celestial bodies. for the earth, the boundary of outer space lies on the Karman line - 100 km above sea level.

The earth is in it. How many meters from you to the room you are sitting in? Still be stricter in words! You didn't mean space, but only airless space, right? Strictly speaking, the atmosphere does not have a clear upper boundary. What signs of "cosmos" are you interested in?
Where you can't breathe? Already at 5 kilometers you can barely exist with shortness of breath. And at 10 - you will suffocate with a guarantee. However, the aircraft is even up to 20 km. there may still be enough air to stay on the wing. Stratostat can rise up to 30 km due to the huge reserve of lift. From this height, the stars are already clearly visible during the day. At 50 km - the sky is already completely black, and yet there is still air - it is there that the aurora "live", which eats nothing more than air ionization. At 100 km. the presence of air is already so small that the apparatus can fly at a speed of several kilometers per second and experience practically no resistance. Unless the instruments can detect the presence of individual air molecules. At 200 km. even the instruments will not show anything, although the number of gas molecules per cubic meter is still much greater than in interplanetary space.
So where does "space" begin?

250 kilometers. a practical question?

NASA considers the boundary of space 122 km

At this altitude, the shuttles switched from conventional maneuvering using only rocket engines to aerodynamic maneuvering with "reliance" on the atmosphere.

There is another point of view that defines the boundary of space at a distance of 21 million kilometers from the Earth - at such a distance, the gravitational influence of the Earth practically disappears.

1000-1100 km - the maximum height of the auroras, the last manifestation of the atmosphere visible from the Earth's surface (but usually well-marked auroras occur at altitudes of 90-400 km).

2000 km - the atmosphere does not affect satellites and they can exist in orbit for many millennia.

100,000 km - the upper boundary of the exosphere (geocorona) of the Earth noticed by satellites. The last manifestations of the earth's atmosphere ended, interplanetary space began.

from 150 km to 300 km, Gagarin flew around the Earth at an altitude of 200 km, and from St. Petersburg to Moscow 650 km

122 km (400,000 ft) - the first noticeable manifestations of the atmosphere during the return to Earth from orbit: the oncoming air begins to turn the Space Shuttle nose in the direction of travel, air ionization from friction and heating of the body begins.

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It is known that outside the earth's atmosphere there is no sign that says "Welcome to space." doesn't end abruptly. Its density decreases gradually. The maximum height at which a spacecraft or any other body is considered to have entered outer space is set at 100 kilometers from the Earth's surface.

Where does space begin?

Can this bar be lowered? Who decides where space begins? Virgin Galactic and its space tourism competitors would like to reduce that height. According to the modern classification, their suborbital flights are not considered space flights. Lowering the space bar will allow them to claim that their customers have been to outer space. Although such a change will not affect Elon Musk if he fulfills his promised flight around the moon.

The boundary of space should not be arbitrary. and space historian Jonathan McDowell argues that the edge of space must be determined by physics. In the middle of the 20th century, scientists tried to establish this limit. They believed that space begins at the height at which an object can maintain a stable orbit. This height is known as the Karman line. It was named after the aerospace engineer Theodor von Karman. Below the Karman line, atmospheric drag becomes too much of a factor to support even a very elliptical orbit. While on it, the object approaches the Earth at certain moments, and then goes much further.

Space closer

For many years, the official Karman line was set at 100 km. But that was not the value Karman had set for him. In an article published earlier this year in the journal Acta Astronautica, McDowell recalculated the Karman Line and found it to be significantly closer—close enough to make private tourist flights a trip. into the space.

The scientist said that the US government has long resisted the definition of an official legal boundary between air and space. Although there is an urgent need for this. Aircraft are subject to airspace regulations, while objects in space are not. Although they are subject to international treaties on the peaceful use of outer space.

When North Korea launched a missile last year, reportedly over Japanese airspace, McDowell said it was actually higher than the .

“Of course she was in space. And it doesn't make sense to say that it is in Japanese airspace," he said. Without an international agreement on the boundary between air and space, such confusion is inevitable.

80 or 100?

He said that scientists had previously tried to calculate the Karman line back in the 1950s and early 1960s. And we got values ​​that are quite close to its value, which was 80 km. But in the late 1960s, it was set at 100 km. Probably, according to the scientist, this was done in order to make it easier to use a beautiful round number in calculations. This value is higher than the maximum flight altitude of aircraft - about 50 km. There is a gap between altitudes, where air allows aircraft to fly, and space, where an object can maintain a stable orbit, he said.

The limitation for space objects is not the same for everyone. Because denser objects can pass through a denser atmosphere and stay in orbit. The feather has a higher pocket limit than the bowling ball. And there are seasonal and regional differences in atmospheric density. But 80 km looks much better to Americans than 100 km. However, such a change revives with new force the old question: who was the first to get into space?

Who was first?

German V-2 rockets would be the first to reach space. This happened in the 1940s. And who are the first people who got into the space? These are the pilots of the X-15 space plane, McDowell said. This joint project of the NASA Department of Defense looked like a rocket with small wings. From 1959 to 1968 he made 200 flights.

Despite setting a Karman limit of 100 km, the US decided to grant astronaut ranks to all X-15 pilots who flew above 80 km.

But, even despite the attempts of American scientists to revise the height at which space begins, the whole world knows who he is. This man undoubtedly accomplished what the Americans failed to do until February 1962 - to make the world's first orbital space flight.

Having an official, legal, science-based definition of space will only remove any ambiguity associated with awarding ranks to American astronauts. It will also help increase the profits of private companies by changing the status of flights. Their activities have already led international organizations to consider making 80 km the official boundary of space.

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A few years ago, another disaster occurred in the United States during the launch of a space shuttle. The spacecraft exploded within seconds of liftoff. A feature of this case is the fact that the dead employees of the American space agency were not included in the list of dead astronauts.

The thing is that, despite the decent height at which the tragedy happened, the “boundary of space” has not yet been crossed. From all this follows a completely logical question - "where does the cosmos begin?". This is what will be discussed next.

No end, no end

Talk about where exactly space begins, starting from what height it can be considered that outer space begins, has been going on for a very long time. The thing is that the very interpretation of the concept of space is very blurred. Due to differences in definitions, scientists cannot agree on the answer to the question about the beginning of the cosmos.

Many scientists, relying on various sciences, note different numbers, trying to establish the point of "the beginning of the cosmos." For example, from the point of view of climatology, experts argue that space begins at a height of 118 km. The thing is that at such a distance from our earth, scientists study the processes of climate formation. However, many note other indicators in relation to outer space. At the same time, many also rely on our atmosphere as a certain milestone. It would seem that everything is simple, our atmosphere has ended and space begins. However, there are also some nuances here. Air, even if very rarefied, has been repeatedly recorded by various instruments at a very large distance from the ground. The same distance goes far beyond our atmosphere.

Scientists studying the issues of radiation, operating on the fact that the cosmos is a radiation space, argue that the cosmos begins where radiation also begins. In turn, scientists studying gravity say that the cosmos begins where the gravitational force of the earth completely “ends”, namely, at a distance of more than twenty million kilometers.

If we rely on the figures proposed by specialists studying gravity, then we can say that the lion's share of all space expeditions cannot be considered as such at all. In addition, with such a "boundary" of space, the very concept of an astronaut is invalid. After all, a distance of twenty million kilometers is a very serious indicator. For comparison, if we take into account these figures, it turns out that space begins only outside the orbit of the moon.

Specialists from the American space agency at one time proposed a mark of 122 km as a starting point. The thing is that when the spacecraft descends to the earth's surface, it is at this altitude that the astronauts turn off the onboard engines and begin the aerodynamic entry. However, this figure is different for domestic cosmonauts. Today, the Americans began to consider 80 km as a "barrier". They took this figure based on the fact that it is at this distance from the earth that a meteorite entering the atmosphere begins to “glow”.

As a summary, it can be noted that, despite the fact that scientists still have not come to a compromise on the issue of the beginning of space, the figure of 100 km has been adopted by the international community as conditionally marking the beginning of space. This figure was taken as such a conditional reference point, since at such an altitude the flight of an aircraft is no longer possible due to the low air density.

how many kilometers from earth to space? and got the best answer

Answer from WinterMax[guru]
as such, there is no clear boundary between the earth's atmosphere and the vacuum of space. As the gas concentration decreases, the pressure decreases as it rises.
It is generally accepted that the atmosphere rises above the earth by about 800 km. But the main layer (and this is 99% of all gas) is located in the first 122 km.
By the way, the distance to the moon is about 380,000 km.

Answer from Alexey Kochetkov[guru]
from the earth to the uppermost shell of the earth 50,000 km
to the moon 80,000 km

Answer from Yoehmet[guru]
Space is considered to begin at the level of 100 km. from the earth.

Answer from Beaver[guru]
The conditional boundary of space is 100 km.
Conditional because there are no stretched ropes with signs: "Attention! Then space begins, flying by planes is strictly prohibited!", We just agreed.
In fact, there are a number of reasons why it was agreed that way, but they, too, are rather arbitrary.

Answer from ****** [guru]
From a height of 30 km already begins

Answer from Hard childhood[guru]
first understand the terms, and then ask questions. space is the whole material world and the distance to it is 0 km. Outer space is a relatively empty part of space outside the atmospheres of celestial bodies. for the earth, the boundary of outer space lies on the Karman line - 100 km above sea level.

Answer from Dmitry Nizyaev[guru]
The earth is in it. How many meters from you to the room you are sitting in? Still be stricter in words! You didn't mean space, but only airless space, right? Strictly speaking, the atmosphere does not have a clear upper boundary. What signs of "cosmos" are you interested in?
Where you can't breathe? Already at 5 kilometers you can barely exist with shortness of breath. And at 10 - you will suffocate with a guarantee. However, the aircraft is even up to 20 km. there may still be enough air to stay on the wing. Stratostat can rise up to 30 km due to the huge reserve of lift. From this height, the stars are already clearly visible during the day. At 50 km - the sky is already completely black, and yet there is still air - it is there that the auroras "live", which are eaten by nothing more than air ionization. At 100 km. the presence of air is already so small that the apparatus can fly at a speed of several kilometers per second and experience practically no resistance. Unless the instruments can detect the presence of individual air molecules. At 200 km. even the instruments will not show anything, although the number of gas molecules per cubic meter is still much greater than in interplanetary space.
So where does "space" begin?

Answer from Igor Borukhin[newbie]
250 kilometers. a practical question?

Answer from Christianity is the religion of progress[guru]
NASA considers the boundary of space 122 km
At this altitude, the shuttles switched from conventional maneuvering using only rocket engines to aerodynamic maneuvering with "reliance" on the atmosphere.
There is another point of view that defines the boundary of space at a distance of 21 million kilometers from the Earth - at such a distance, the gravitational influence of the Earth practically disappears.

Answer from NAMIK[newbie]
128 km

Answer from Chernobushka[expert]

1000-1100 km - the maximum height of the auroras, the last manifestation of the atmosphere visible from the Earth's surface (but usually well-marked auroras occur at altitudes of 90-400 km).
2000 km - the atmosphere does not affect satellites and they can exist in orbit for many millennia.
100,000 km - the upper boundary of the exosphere (geocorona) of the Earth noticed by satellites. The last manifestations of the earth's atmosphere ended, interplanetary space began.

Answer from Yana Mazina[newbie]
from 150 km to 300 km, Gagarin flew around the Earth at an altitude of 200 km, and from St. Petersburg to Moscow 650 km

Answer from Magneto[active]
122 km (400,000 ft) - the first noticeable manifestations of the atmosphere during the return to Earth from orbit: the oncoming air begins to turn the Space Shuttle nose in the direction of travel, air ionization from friction and heating of the body begins.

Answer from Yotudia Creative[newbie]
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Answer from [email protected] [newbie]
So many selfies and other shit from the ground, why are there no adequate shootings from space and flights?! Only monotonous mounting cuts .. and illogical conditions for existence in orbit