Boundaries on the way to space and the limits of deep space

Boundaries on the way to space and the limits of deep space - a unique article with a lot of data about which you have hardly heard.

• Sea level - 101, 3 kPa (1 atm; 760 mm Hg;) atmospheric pressure, density of the medium 2, 7 · 1019 molecules per cm³.

• 0.5 km - 80% of the world's population lives up to this height.

• 2 km - 99% of the world's population live up to this height.

• 2-3 km - the beginning of manifestation of ailments (altitude sickness) in non-acclimatized people.

• 4.7 km - MFA requires additional oxygen supply for pilots and passengers.

• 5.0 km - 50% of the atmospheric pressure at sea level.

• 5, 3 km - half of the entire mass of the atmosphere lies below this height (slightly below the summit of Mount Elbrus).

• 6 km - the border of permanent human habitation.

• 7 km - the limit of adaptability to a long stay.

• 8, 2 km - the border of death without an oxygen mask: even a healthy and trained person can lose consciousness and die at any time.

• 8, 848 km - the highest point of the Earth is Mount Everest - the limit of accessibility on foot.

• 9 km - the limit of adaptability to short-term breathing of atmospheric air.

• 12 km - breathing air is equivalent to being in space (the same time of loss of consciousness ~ 10-20 s); limit of short-term breathing of pure oxygen without additional pressure; ceiling of subsonic passenger liners.

• 15 km - breathing pure oxygen is equivalent to being in space.

• 16 km - when in a high-altitude suit, additional pressure is required in the cockpit. 10% of the atmosphere is left overhead.

• 10-18 km - the border between the troposphere and the stratosphere at different latitudes (tropopause).

• 18, 9–19, 35 - Armstrong's line - the beginning of space for the human body - water boiling at the temperature of the human body. Internal bodily fluids at this altitude do not boil yet, since the body generates enough internal pressure to prevent this effect, but saliva and tears can begin to boil with the formation of foam, and the eyes swell.

• 19 km - the brightness of the dark purple sky at the zenith 5% of the brightness of the clear blue sky at sea level (74, 3-75 candles against 1500 candles per m²), the brightest stars and planets can be seen during the day.

• 20 km - the upper boundary of the biosphere: the limit of the ascent of spores and bacteria into the atmosphere by air currents.

• 20 km - the intensity of the primary cosmic radiation begins to prevail over the secondary (born in the atmosphere).

• 20 km - ceiling of hot air balloons (hot air balloons) (19, 811 m).

• 25 km - during the day you can navigate by bright stars.

• 25-26 km is the maximum steady-state flight altitude of existing jet aircraft (service ceiling).

• 15-30 km - ozone layer at different latitudes.

• 34, 668 km - an altitude record for a balloon (stratospheric balloon) controlled by two stratonauts.

• 35 km - the beginning of space for water or a triple point of water: at this altitude, water boils at 0 ° C, and above it cannot be in liquid form.

• 37, 65 km - record for the height of existing turbojet aircraft (Mig-25, dynamic ceiling).

• 38, 48 km (52, 000 steps) - the upper limit of the atmosphere in the 11th century: the first scientific determination of the height of the atmosphere by the duration of twilight (Arabic scientist Algazen, 965-1039).

• 39 km - record for the height of a stratospheric balloon controlled by a man (Red Bull Stratos).

• 45 km is the theoretical limit for a ramjet aircraft.

• 48 km - the atmosphere does not attenuate the sun's ultraviolet rays.

• 50 km - the border between the stratosphere and the mesosphere (stratopause).

• 51, 694 km - the last manned altitude record in the pre-space era (Joseph Walker on the X-15 rocket plane, March 30, 1961)

• 51, 82 km - record altitude for a gas unmanned balloon.

• 55 km - the atmosphere does not affect space radiation.

• 40-80 km - maximum ionization of air (transformation of air into plasma) from friction against the body of the descent vehicle when entering the atmosphere at the first space velocity.

• 70 km - the upper limit of the atmosphere in 1714 as calculated by Edmund Holly (Halley) based on climbers' data, Boyle's law and meteor observations.

• 80 km - border between the mesosphere and thermosphere (mesopause).

• 80, 45 km (50 mi) is the official height of the US space boundary.

• 100 km - the official international boundary between the atmosphere and space - the Karman Line, which defines the boundary between aeronautics and astronautics. Aerodynamic surfaces (wings), starting from this height, do not make sense, since the flight speed to create lift becomes higher than the first cosmic speed and the atmospheric aircraft turns into a space satellite. The density of the medium at this height is 12 billion molecules per 1 cm³

• 100 km - the registered boundary of the atmosphere in 1902: the discovery of the reflecting radio waves of the ionized Kennelly-Heaviside layer 90-120 km.

• 118 km - transition from atmospheric wind to streams of charged particles.

• 122 km (400, 000 feet) - the first noticeable manifestations of the atmosphere during the return to Earth from orbit: the incoming air begins to unfold the Space Shuttle with its nose in the direction of travel, ionization of the air from friction and heating of the hull begins.

• 120-130 km - a satellite in a circular orbit with such an altitude can make no more than one revolution.

• 150-180 km - orbital perigee altitude of the first manned space flights.

• 200 km - the lowest possible orbit with short-term stability (up to several days).

• 302 km - the maximum height of the first space flight (Gagarin Yu.A., Vostok-1, April 12, 1961)

• 320 km - recorded boundary of the atmosphere in 1927: discovery of the Appleton layer reflecting radio waves.

• 350 km - the lowest possible orbit with long-term stability (up to several years).

• OK. 400 km - orbital altitude of the International Space Station

• 500 km - the beginning of the inner proton radiation belt and the end of safe orbits for long-term human flights.

• 690 km - border between thermosphere and exosphere.

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

• 1372 km - the maximum height reached by man in the lunar epoch (September 12, 1966, Gemini-11).

• 2000 km - the atmosphere has no effect on satellites and they can exist in orbit for many millennia.

• 3000 km - the maximum intensity of the proton flux of the inner radiation belt (up to 0.5-1 Gy / hour).

• 12 756 km - we moved away at a distance equal to the diameter of the planet Earth.

• 17, 000 km - outer electronic radiation belt.

• 27, 000 km - the smallest distance from the Earth, at which the discovered asteroid 2012 DA14 with a diameter of 44 m and a mass of about 130 thousand tons flew in advance (over 1 day).

• 35 786 km - the height of the geostationary orbit, the satellite at this height will always hang over one point of the equator. In the first half of the 20th, this height was considered the theoretical limit of the existence of the atmosphere. If the entire atmosphere rotated uniformly together with the Earth, then from this height at the equator the centrifugal force of rotation will exceed the gravity and air particles that have gone beyond this boundary will scatter in different directions.

• OK. 90, 000 km is the distance to the head shock wave formed by the collision of the Earth's magnetosphere with the solar wind.

• OK. 100, 000 km is the upper boundary of the Earth's exosphere (geocorona) seen by satellites. The atmosphere is over, interplanetary space begins

• 363 104 - 405 696 km - the height of the Moon's orbit above the Earth.

• 401, 056 km - an absolute record for the height at which a person was (Apollo 13, April 14, 1970).

• 930, 000 km - the radius of the Earth's gravitational sphere and the maximum height of the existence of its satellites. Above 930, 000 km, the Sun's gravity begins to prevail and it will pull the bodies that have risen higher.

• 1, 500, 000 km - the distance to one of the libration points L2, at which the bodies that have got there are in gravitational equilibrium. A space station launched to this point, without being an orbiting satellite, with minimal fuel consumption for trajectory correction would always follow the Earth and would be in its shadow.

• 21, 000, 000 km - at this distance, the Earth's gravitational effect on passing objects practically disappears.

• 40, 000, 000 km - the minimum distance from the Earth to the nearest large planet Venus (56-58 million km to Mars).

• 149 597 870, 7 km - the average distance from the Earth to the Sun. This distance serves as a measure of distances in the solar system and is called the astronomical unit (AU).

• 4 500 000 000 km - the radius of the boundary of the near-solar interplanetary space - the radius of the orbit of the farthest large planet Neptune.

• 8, 230, 000, 000 km - the border of the Kuiper belt - the belt of small ice planets.

• 18 435 000 000 km - the distance to the farthest spacecraft Voyager 1 today.

• Several tens of billions of kilometers - the range of the solar wind, the boundary of the heliosphere, the beginning of interstellar space.

• 9 460 730 472 580, 8 km - light year - the distance that light travels in 1 year. Serves for measuring interstellar and intergalactic distances.

• up to 20, 000, 000, 000, 000 km (20 trillion km, 2 light years) - the gravitational boundaries of the Solar System (Hill's Sphere) - the boundary of the Oort Cloud, the maximum range of the existence of planets.

• 30, 856, 776, 000, 000 km - parsec - a more narrowly professional astronomical unit of distance measurement, equal to 3.2616 light years.

• OK. 40, 000, 000, 000, 000 km (40 trillion km, 4, 243 light years) - the distance to the nearest star Proxima Centauri

• OK. 300, 000, 000, 000, 000 km (300 trillion km, 30 light years) is the size of the Local interstellar cloud through which the Solar System is now moving (density of 300 atoms per 1 dm³).

• OK. 3, 000, 000, 000, 000, 000 km (3 quadrillion km, 300 light years) is the size of the Local Gas Bubble, which includes the Local Interstellar Cloud with the Solar System (50 atoms per 1 dm³).

• OK. 33, 000, 000, 000, 000, 000 km (33 kvdrln km, 3500 light years) is the thickness of the Orion Galactic Arm, which contains the Local Bubble.

• OK. 300, 000, 000, 000, 000, 000 km (300 kvdrln km) is the distance from the Sun to the closest outer edge of the halo of our Milky Way galaxy. Outside it stretches a black, almost empty and starless intergalactic space with small spots of several nearby galaxies barely discernible without a telescope.

• OK. 2, 000, 000, 000, 000, 000, 000, 000, 000, 000 km is the border of the Milky Way subgroup (15 galaxies).

• OK. 15, 000, 000, 000, 000, 000, 000 km (15 quintillion km) is the boundary of the Local Group of galaxies (over 50 galaxies).

• OK. 1, 000, 000, 000, 000, 000, 000, 000 km (1 sextillion km, 100 million light years) - the border of the Local Supercluster of galaxies (Virgo Supercluster) (about 30 thousand galaxies).

• The Kita-Pisces supercluster group

• OK. 435, 000, 000, 000, 000, 000, 000, 000 km (435 sextillion km, 46 billion light years) is the boundary of the observable Universe (about 500 billion galaxies).