Citizendia

Outer space, often simply called space, refers to the relatively empty regions of the universe outside the atmospheres of celestial bodies. The Universe is defined as everything that Physically Exists: the entirety of Space and Time, all forms of Matter, Energy An atmosphere (from Greek ατμός - atmos, " Vapor " + σφαίρα - sphaira, " Sphere " s are significant physical entities, associations or structures which current Science has confirmed to exist in Space. Outer space is used to distinguish it from airspace (and terrestrial locations). Airspace means the portion of the atmosphere controlled by a particular country on top of its territory and Territorial waters or more generally any specific three-dimensional Contrary to popular understanding, outer space is not completely empty (i. e. a perfect vacuum) but contains a low density of particles, predominantly hydrogen plasma, as well as electromagnetic radiation. This vacuum means "absence of matter" or "an empty area or space" for the cleaning appliance see Vacuum cleaner. In Physics and Chemistry, plasma is an Ionized Gas, in which a certain proportion of Electrons are free rather than being bound Electromagnetic radiation takes the form of self-propagating Waves in a Vacuum or in Matter. Hypothetically, it also contains dark matter and dark energy. In Physics and cosmology, dark matter is hypothetical Matter that does not interact with the electromagnetic force but whose presence can be inferred from In Physical cosmology, dark energy is a hypothetical exotic form of Energy that permeates all of space and tends to increase the rate of expansion of the universe

The term "outer space" was first recorded by H. G. Wells in 1901. Herbert George Wells (21 September 1866 &ndash 13 August 1946 He was an outspoken socialist and a pacifist, his later works becoming increasingly political [1] The shorter term space is actually older, being first used to mean the region beyond Earth's sky in John Milton's Paradise Lost in 1667. John Milton ( 9 December, 1608 – 8 November, 1674) was an English Poet, Prose Polemicist and Paradise Lost is an Epic poem in Blank verse by the 17th-century English poet John Milton. [2]

Contents

Environment

Outer space is not a perfect vacuum, but a tenuous plasma awash with charged particles, electromagnetic fields, and the occasional star.
Outer space is not a perfect vacuum, but a tenuous plasma awash with charged particles, electromagnetic fields, and the occasional star. In Physics and Chemistry, plasma is an Ionized Gas, in which a certain proportion of Electrons are free rather than being bound The electromagnetic field is a physical field produced by electrically charged objects. A star is a massive luminous ball of plasma. The nearest star to Earth is the Sun, which is the source of most of the Energy on Earth

Outer space is the closest physical approximation of a perfect vacuum. This vacuum means "absence of matter" or "an empty area or space" for the cleaning appliance see Vacuum cleaner. It has effectively no friction, allowing stars, planets and moons to move freely along ideal gravitational trajectories. Friction is the Force resisting the relative motion of two Surfaces in contact or a surface in contact with a fluid (e A star is a massive luminous ball of plasma. The nearest star to Earth is the Sun, which is the source of most of the Energy on Earth A planet, as defined by the International Astronomical Union (IAU is a celestial body Orbiting a Star or stellar remnant that is But no vacuum is truly perfect, not even in interstellar space where there are still a few hydrogen atoms per cubic centimeter. (For comparison, the air we breathe contains about 1019 molecules per cubic centimeter. ) The deep vacuum of space could make it an attractive environment for certain industrial processes, for instance those that require ultraclean surfaces; however, it is currently much less costly to create an equivalent vacuum on Earth than to leave the Earth's gravity well. In Physics, a gravity well is the Gravitational potential field around a massive body (a particular kind of Potential well)

Stars, planets and moons keep their atmospheres by gravitational attraction, and as such, atmospheres have no clearly delineated boundary: the density of atmospheric gas simply decreases with distance from the object. An atmosphere (from Greek ατμός - atmos, " Vapor " + σφαίρα - sphaira, " Sphere " The Earth's atmospheric pressure drops to about 1 Pa (10-3 Torr) at 100 km of altitude, the Kármán line which is a common definition of the boundary with outer space. Beyond this line, isotropic gas pressure rapidly becomes insignificant when compared to radiation pressure from the sun and the dynamic pressure of the solar wind, so the definition of pressure becomes difficult to interpret. Radiation pressure is the Pressure exerted upon any surface exposed to Electromagnetic radiation. The Sun (Sol is the Star at the center of the Solar System. In Fluid dynamics dynamic pressure (indicated with q, or Q, and sometimes called velocity pressure) is the quantity defined by The solar wind is a Stream of charged particles&mdasha plasma &mdashthat are ejected from the upper atmosphere of the Sun. The thermosphere in this range has large gradients of pressure, temperature and composition, and varies greatly due to space weather. The thermosphere is the layer of the Earth's atmosphere directly above the Mesosphere and directly below the Exosphere. Space weather is the concept of changing environmental conditions in Outer space. Astrophysicists prefer to use number density to describe these environments, in units of particles per cubic centimetre. In Physics, Astronomy, and Chemistry, number density is an Intensive quantity used to describe the degree of concentration of Countable

But although it meets the definition of outer space, the atmospheric density within the first few hundred kilometers above the Kármán line is still sufficient to produce significant drag on satellites. In Fluid dynamics, drag (sometimes called fluid resistance) is the force that resists the movement of a Solid object through a Fluid (a This article is about artificial satellites For natural satellites also known as moons see Natural satellite. Most artificial satellites operate in this region called low earth orbit and must fire their engines every few days to maintain orbit. A Low Earth Orbit (LEO is generally defined as an Orbit within the locus extending from the Earth’s surface up to an altitude of 2000 km The drag here is low enough that it could theoretically be overcome by radiation pressure on solar sails, a proposed propulsion system for interplanetary travel. Solar sails (also called light sails or photon sails, especially when they use Light sources other than the Sun) are a proposed form of Planets are too massive for their trajectories to be affected by these forces, although their atmospheres are eroded by the solar winds.

All of the observable universe is filled with large numbers of photons, the so-called cosmic background radiation, and quite likely a correspondingly large number of neutrinos. The Universe is defined as everything that Physically Exists: the entirety of Space and Time, all forms of Matter, Energy In Physics, the photon is the Elementary particle responsible for electromagnetic phenomena Neutrinos are Elementary particles that travel close to the Speed of light, lack an Electric charge, are able to pass through ordinary matter almost The current temperature of this radiation is about 3 K, or −270 °C (−454. Temperature is a physical property of a system that underlies the common notions of hot and cold something that is hotter generally has the greater temperature The kelvin (symbol K) is a unit increment of Temperature and is one of the seven SI base units The Kelvin scale is a thermodynamic 00 °F).

Contrary to popular belief,[3] a person suddenly exposed to the vacuum would not explode, freeze to death or die from boiling blood, but would take a short while to die by asphyxiation (suffocation). This vacuum means "absence of matter" or "an empty area or space" for the cleaning appliance see Vacuum cleaner. Hypothermia is a condition in which an organism's temperature drops below that required for normal Metabolism and bodily functions Air would immediately leave the lungs due to the enormous pressure gradient. Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five lung is the essential Respiration organ in air-breathing Animals including most Tetrapods a few Fish and a few Snails The most primitive In atmospheric sciences ( Meteorology, Climatology and related fields the pressure gradient (typically of air, more generally of any Fluid) Any oxygen dissolved in the blood would empty into the lungs to try to equalize the partial pressure gradient. Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the In a mixture of Ideal gases each gas has a partial pressure which is the pressure which the gas would have if it alone occupied the volume Once the deoxygenated blood arrived at the brain, death would quickly follow.

Humans and animals exposed to vacuum will lose consciousness after a few seconds and die of hypoxia within minutes. Consciousness has been defined loosely as a constellation of attributes of Mind such as Subjectivity, Self-awareness, Sentience, and the Blood and other body fluids do boil when their pressure drops below 6. Blood is a specialized Bodily fluid that delivers necessary substances to the body's cells such as nutrients and oxygen—and transports Waste products 3 kPa, (47 Torr,) the vapor pressure of water at body temperature. Vapor pressure (also known as equilibrium vapor pressure or saturation vapor pressure) is the Pressure of a Vapor in equilibrium [4] This condition is called ebullism. Ebullism is the formation of Gas bubbles in Bodily fluids due to reduced environmental pressure for example at high Altitude. The steam may bloat the body to twice its normal size and slow circulation, but tissues are elastic and porous enough to prevent rupture. Ebullism is slowed by the pressure containment of blood vessels, so some blood remains liquid. [5][6] Swelling and ebullism can be reduced by containment in a flight suit. flight suit is a full body garment worn while flying a powered Aircraft such as Military airplanes and helicopters Shuttle astronauts wear a fitted elastic garment called the Crew Altitude Protection Suit (CAPS) which prevents ebullism at pressures as low as 2 kPa (15 Torr). NASA 's Space Shuttle, officially called Space Transportation System ( STS) is the United States government's current manned Launch [7] Water vapor would also rapidly evaporate off from exposed areas such as the lungs, cornea of the eye and mouth, cooling the body. General properties of water vapor Evaporation/sublimation Whenever a water molecule leaves a surface it is said to have evaporated Evaporation is the process by which Molecules in a Liquid state (e The cornea is the transparent front part of the Eye that covers the iris, Pupil, and Anterior chamber. Eyes are organs that detect Light, and send signals along the Optic nerve to the visual areas of the brain Rapid evaporative cooling of the skin will create frost, particularly in the mouth, but this is not a significant hazard. Space may be cold, but it's mostly vacuum and can hardly transfer heat, so the main temperature worry for space suits is how to get rid of naturally generated body heat.

Cold or oxygen-rich atmospheres can sustain life at pressures much lower than atmospheric, as long as the density of oxygen is similar to that of standard sea-level atmosphere. The colder air temperatures found at altitudes of up to 3 km generally compensate for the lower pressures there. [4] Above this altitude, oxygen enrichment is necessary to prevent altitude sickness, and spacesuits are necessary to prevent ebullism above 19 km. Altitude sickness, also known as acute mountain sickness ( AMS) altitude illness, or soroche, is a pathological condition that is caused by acute A space suit is a complex system of Garments equipment and environmental systems designed to keep a person alive and comfortable in the harsh environment of outer space [4] Most spacesuits use only 20 kPa (150 Torr) of pure oxygen, just enough to sustain full consciousness. This pressure is high enough to prevent ebullism, but simple evaporation of blood can still cause decompression sickness and gas embolisms if not managed. Evaporation is the process by which Molecules in a Liquid state (e Decompression sickness (DCS, the diver’s disease, the bends, caisson disease is the name given to a variety of symptoms suffered by a person An air embolism, or more generally gas embolism, is a medical condition caused by Gas bubbles in the bloodstream ( embolism in a medical context refers to

Rapid decompression can be much more dangerous than vacuum exposure itself. Even if the victim does not hold his breath, venting through the windpipe may be too slow to prevent the fatal rupture of the delicate alveoli of the lungs. An alveolus (plural alveoli, from Latin alveolus, "little cavity" is an anatomical structure that has the form of a hollow cavity lung is the essential Respiration organ in air-breathing Animals including most Tetrapods a few Fish and a few Snails The most primitive [4] Eardrums and sinuses may be ruptured by rapid decompression, soft tissues may bruise and seep blood, and the stress of shock will accelerate oxygen consumption leading to hypoxia. The tympanic membrane (also tympanum or myrinx is a thin membrane that separates the External ear from the Middle ear. [8] Injuries caused by rapid decompression are called barotrauma. Barotrauma is physical damage to body tissues caused by a difference in Pressure between an air space inside or beside the body and the surrounding Gas or Liquid A pressure drop as small as 100 Torr, (13 kPa,) which produces no symptoms if it is gradual, may be fatal if occurs suddenly. [4]

Space versus orbit

To perform an orbital spaceflight, a spacecraft must travel faster than it must for a sub-orbital spaceflight. An orbital spaceflight (or orbital flight is a Spaceflight in which a Spacecraft is placed on a trajectory where it could remain in space for at least A sub-orbital spaceflight (or sub-orbital flight is a Spaceflight in which the Spacecraft reaches space, but its Trajectory intersects A spacecraft has not entered orbit until it is traveling with a sufficiently great horizontal velocity such that the acceleration due to gravity on the spacecraft is less than or equal to the centripetal acceleration being caused by its horizontal velocity (see circular motion). In Physics, an orbit is the gravitationally curved path of one object around a point or another body for example the gravitational orbit of a planet around a star Gravitation is a natural Phenomenon by which objects with Mass attract one another The centripetal force is the external force required to make a body follow a curved path In Physics, circular motion is Rotation along a Circle: a circular path or a circular Orbit. So to enter orbit, a spacecraft must not only reach space, but must also achieve a sufficient orbital speed (angular velocity). In Physics, an orbit is the gravitationally curved path of one object around a point or another body for example the gravitational orbit of a planet around a star The orbital speed of a body generally a Planet, a Natural satellite, an artificial satellite, or a Multiple star, is the speed at which it Do not confuse with Angular frequency The unit for angular velocity is rad/s For a low-Earth orbit, this is about 7. 9 km/s (18,000 mph); by contrast, the fastest airplane speed ever achieved (excluding speeds achieved by deorbiting spacecraft) was 2. 02 km/s (4,520 mph) in 1967 by the North American X-15[9]. Konstantin Tsiolkovsky was the first person to realize that, given the energy available from any available chemical fuel, a several-stage rocket would be required. In Physics and other Sciences energy (from the Greek grc ἐνέργεια - Energeia, "activity operation" from grc ἐνεργός Chemistry (from Egyptian kēme (chem meaning "earth") is the Science concerned with the composition structure and properties Fuel is any material that is burned or altered in order to obtain energy A rocket or rocket vehicle is a Missile, Aircraft or other Vehicle which obtains Thrust by the reaction of the The escape velocity to pull free of Earth's gravitational field altogether and move into interplanetary space is about 40,000 km/h (25,000 mph or 11,000 m/s). In Physics, escape velocity is the speed where the Kinetic energy of an object is equal to the magnitude of its Gravitational potential energy Outer space, often simply called space, comprises the relatively empty regions of the Universe outside the escape velocities of Celestial bodies. The energy required to reach velocity for low Earth orbit (32 MJ/kg) is about twenty times the energy required simply to climb to the corresponding altitude (10 kJ/(km·kg)). The joule (written in lower case ˈdʒuːl or /ˈdʒaʊl/ (symbol J) is the SI unit of Energy measuring heat, Electricity

There is a major difference between sub-orbital and orbital spaceflights. A sub-orbital spaceflight (or sub-orbital flight is a Spaceflight in which the Spacecraft reaches space, but its Trajectory intersects An orbital spaceflight (or orbital flight is a Spaceflight in which a Spacecraft is placed on a trajectory where it could remain in space for at least The minimum altitude for a stable orbit around Earth (that is, one without significant atmospheric drag) begins at around 350 km (220 miles) above mean sea level. In Fluid dynamics, drag (sometimes called fluid resistance) is the force that resists the movement of a Solid object through a Fluid (a A common misunderstanding about the boundary to space is that orbit occurs simply by reaching this altitude. Achieving orbital speed can theoretically occur at any altitude, although atmospheric drag precludes an orbit that is too low. At sufficient speed, an airplane would need a way to keep it from flying off into space, but at present, this speed is several times greater than anything within reasonable technology.

Regions

Space being not a perfect vacuum, its different regions are defined by the various atmospheres and "winds" that dominate within them, and extend to the point at which those winds give way to those beyond. Geospace extends from Earth's atmosphere to the outer reaches of Earth's magnetic field, whereupon it gives way to the solar wind of interplanetary space. The solar wind is a Stream of charged particles&mdasha plasma &mdashthat are ejected from the upper atmosphere of the Sun. Interplanetary space extends to the heliopause, whereupon the solar wind gives way to the winds of the interstellar medium. The heliosphere is a bubble in space "blown" into the Interstellar medium (the hydrogen and helium gas that permeates the Galaxy) by the Interstellar space then continues to the edges of the galaxy, where it fades into the intergalactic void.

Geospace

Geospace (dark blue).
Geospace (dark blue).

In the context of space weather, geospace is the region of outer space near the Earth. Space weather is the concept of changing environmental conditions in Outer space. Geospace includes the upper region of the atmosphere, as well as the ionosphere and magnetosphere. Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five The ionosphere is the uppermost part of the atmosphere, distinguished because it is Ionized by solar radiation A magnetosphere' is a highly magnetized region around and possessed by an Astronomical object. The Van Allen radiation belts also lie within the geospace. The Van Allen radiation belt is a Torus of energetic Charged particles ( plasma) around Earth, held in place by Earth's Magnetic

There is no clear boundary between Earth's atmosphere and space as the density of the atmosphere gradually decreases as the altitude increases. Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different Altitude is the Elevation of a point or object from a known level or datum (plural data Nevertheless, the Fédération Aéronautique Internationale has established the Kármán line at an altitude of 100 km (62 miles) as a working definition for the boundary between aeronautics and astronautics. The Fédération Aéronautique Internationale (FAI is the world governing body for Air sports and Aeronautics and Astronautics world records The kilometre ( American spelling: kilometer) symbol km is a unit of Length in the Metric system, equal to one thousand A mile is a unit of Length, usually used to measure Distance, in a number of different systems including Imperial units United States This is used because above an altitude of roughly 100 km, as Theodore von Kármán calculated, a vehicle would have to travel faster than orbital velocity in order to derive sufficient aerodynamic lift from the atmosphere to support itself. The orbital speed of a body generally a Planet, a Natural satellite, an artificial satellite, or a Multiple star, is the speed at which it In the context of a Fluid flow relative to a body the lift force is the component of the Aerodynamic force that is Perpendicular to the flow The United States designates people who travel above an altitude of 80 km (50 statute miles) as astronauts. The United States of America —commonly referred to as the An astronaut or cosmonaut (космона́вт) is a person trained During re-entry, roughly 120 km (75 miles) marks the boundary where atmospheric drag becomes noticeable, depending on the ballistic coefficient of the vehicle. In Fluid dynamics, drag (sometimes called fluid resistance) is the force that resists the movement of a Solid object through a Fluid (a The ballistic coefficient ( BC) of a body is a measure of its ability to overcome air resistance in flight

Geospace is populated at very low densities by electrically charged particles, whose motions are controlled by the Earth's magnetic field. Earth 's magnetic field (and the surface magnetic field) is approximately a Magnetic dipole, with one pole near the North pole (see These plasmas form a medium from which storm-like disturbances powered by the solar wind can drive electrical currents into the Earth’s upper atmosphere. The solar wind is a Stream of charged particles&mdasha plasma &mdashthat are ejected from the upper atmosphere of the Sun.

During geomagnetic storms two regions of geospace, the radiation belts and the ionosphere, can become strongly disturbed. A geomagnetic storm or solar storm is a temporary disturbance of the Earth 's Magnetosphere caused by a disturbance in Space weather. These disturbances interfere with the functioning of satellite communications and navigation (GPS) technologies. Basic concept of GPS operation A GPS receiver calculates its position by carefully timing the signals sent by the constellation of GPS Satellites high above the Earth These storms increase fluxes of energetic electrons that can permanently damage satellite electronics, and can also be a hazard to astronauts, even in low-Earth orbit. A Low Earth Orbit (LEO is generally defined as an Orbit within the locus extending from the Earth’s surface up to an altitude of 2000 km

A common misconception is that people in orbit are outside Earth's gravity because they are "floating". Gravitation is a natural Phenomenon by which objects with Mass attract one another They are floating because they are in "free fall": they are accelerating toward Earth, along with their spacecraft, but are simultaneously moving sideways fast enough that the "fall" away from a straight-line path merely keeps them in orbit at a constant distance above Earth's surface. Free fall is motion with no Acceleration other than that provided by Gravity. Earth's gravity reaches out far past the Van Allen belt and keeps the Moon in orbit at an average distance of 384,403 km (238,857 miles). The Van Allen radiation belt is a Torus of energetic Charged particles ( plasma) around Earth, held in place by Earth's Magnetic

Geospace contains material left over from previous manned and unmanned launches that are a potential hazard to spacecraft. A spacecraft is a Vehicle or machine designed for Spaceflight. Some of this debris re-enters Earth's atmosphere periodically. Space debris or orbital debris, also called space junk and space waste are the objects in Orbit around Earth created by humans that no

The absence of air makes geospace (and the surface of the Moon) ideal locations for astronomy at all wavelengths of the electromagnetic spectrum, as evidenced by the spectacular pictures sent back by the Hubble Space Telescope, allowing light from about 13. Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five Astronomy (from the Greek words astron (ἄστρον "star" and nomos (νόμος "law" is the scientific study The electromagnetic (EM spectrum is the range of all possible Electromagnetic radiation frequencies The Hubble Space Telescope ( HST; also known colloquially as "the Hubble" or just "Hubble" is a space telescope that was carried into 7 billion years ago — almost to the time of the Big Bang — to be observed.

The outer boundary of geospace is the interface between the magnetosphere and the solar wind. The inner boundary is the ionosphere. [10] Alternately, geospace is the region of space between the Earth’s upper atmosphere and the outermost reaches of the Earth’s magnetic field. [11] The region between Earth's atmosphere and the Moon is sometimes referred to as cis-Lunar space.

Interplanetary

Main article: Interplanetary medium

Outer space within the solar system is called interplanetary space, which passes over into interstellar space at the heliopause. The interplanetary medium is the material which fills the solar system and through which all the larger solar system bodies such as Planets Asteroids The Solar System consists of the Sun and those celestial objects bound to it by Gravity. The heliosphere is a bubble in space "blown" into the Interstellar medium (the hydrogen and helium gas that permeates the Galaxy) by the The vacuum of outer space is not really empty; it is sparsely filled with cosmic rays, which include ionized atomic nuclei and various subatomic particles. This vacuum means "absence of matter" or "an empty area or space" for the cleaning appliance see Vacuum cleaner. For the 1962 Bruce Conner film see Cosmic Ray (film Cosmic rays are energetic particles originating from space that impinge on An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge The nucleus of an Atom is the very dense region consisting of Nucleons ( Protons and Neutrons, at the center of an atom A subatomic particle is an elementary or composite Particle smaller than an Atom. There is also gas, plasma and dust, small meteors, and several dozen types of organic molecules discovered to date by microwave spectroscopy. In Physics and Chemistry, plasma is an Ionized Gas, in which a certain proportion of Electrons are free rather than being bound Organic chemistry is a discipline within Chemistry which involves the scientific study of the structure properties composition reactions, and preparation In Chemistry, a molecule is defined as a sufficiently stable electrically neutral group of at least two Atoms in a definite arrangement held together by Rotational spectroscopy or microwave spectroscopy studies the absorption and emission Electromagnetic radiation (typically in the Microwave Interplanetary space is defined by the solar wind, a continuous stream of charged particles emanating from the Sun that creates a very tenuous atmosphere (the heliosphere) for billions of miles into space. The solar wind is a Stream of charged particles&mdasha plasma &mdashthat are ejected from the upper atmosphere of the Sun. The heliosphere is a bubble in space "blown" into the Interstellar medium (the hydrogen and helium gas that permeates the Galaxy) by the The discovery since 1995 of extrasolar planets means that other stars must possess their own interplanetary media. An extrasolar planet, or exoplanet, is a Planet beyond the Solar System, orbiting around other Stars As of September 2008 312

Interstellar

Main article: Interstellar medium

Interstellar space is the physical space within a galaxy not occupied by stars or their planetary systems. A galaxy is a massive gravitationally bound system consisting of Stars an Interstellar medium of gas and dust, and Dark matter A star is a massive luminous ball of plasma. The nearest star to Earth is the Sun, which is the source of most of the Energy on Earth The interstellar medium resides – by definition – in interstellar space.

Intergalactic

Main articles: Intracluster medium and Cosmic microwave background

Intergalactic space is the physical space between galaxies. In Astronomy, the intracluster medium (or ICM is the superheated gas present at the center of a Galaxy cluster. A galaxy is a massive gravitationally bound system consisting of Stars an Interstellar medium of gas and dust, and Dark matter Generally free of dust and debris, intergalactic space is very close to a total vacuum. This vacuum means "absence of matter" or "an empty area or space" for the cleaning appliance see Vacuum cleaner. Some theories put the average density of the Universe as the equivalent of one hydrogen atom per cubic meter[12][13]. The Universe is defined as everything that Physically Exists: the entirety of Space and Time, all forms of Matter, Energy History See also Atomic theory, Atomism The concept that matter is composed of discrete units and cannot be divided into arbitrarily tiny The density of the Universe, however, is clearly not uniform; it ranges from relatively high density in galaxies (including very high density in structures within galaxies, such as planets, stars, and black holes) to conditions in vast voids that have much lower density than the Universe's average. A planet, as defined by the International Astronomical Union (IAU is a celestial body Orbiting a Star or stellar remnant that is A star is a massive luminous ball of plasma. The nearest star to Earth is the Sun, which is the source of most of the Energy on Earth A black hole is a theoretical region of space in which the Gravitational field is so powerful that nothing not even Electromagnetic radiation (e The temperature is only 2. 73 Kelvin[14]. The kelvin (symbol K) is a unit increment of Temperature and is one of the seven SI base units The Kelvin scale is a thermodynamic NASA's COBE mission (Cosmic Background Explorer) measured the temperature as 2. The National Aeronautics and Space Administration ( NASA, ˈnæsə is an agency of the United States government, responsible for the nation's public space program 725 +/- 0. 002 K.

Milestones

See also

References

  1. ^ Etymonline : Outer. Gemini 11 (officially Gemini XI) was a 1966 Manned spaceflight in NASA 's Gemini program. The Agena target vehicle (ATV was a Spacecraft used by NASA to develop and practice orbital Space rendezvous and docking techniques in preparation for The Van Allen radiation belt is a Torus of energetic Charged particles ( plasma) around Earth, held in place by Earth's Magnetic The Van Allen radiation belt is a Torus of energetic Charged particles ( plasma) around Earth, held in place by Earth's Magnetic Basic concept of GPS operation A GPS receiver calculates its position by carefully timing the signals sent by the constellation of GPS Satellites high above the Earth A geostationary orbit (GEO is a Geosynchronous orbit directly above the Earth 's Equator (0° Latitude) with a period equal to the Earth's The Van Allen radiation belt is a Torus of energetic Charged particles ( plasma) around Earth, held in place by Earth's Magnetic In Celestial mechanics, an apsis, plural apsides (ˈæpsɨdɪːz is the point of greatest or least distance of the Elliptical orbit of an object from The Astronaut Badge is a Badge of the United States, awarded to military and civilian pilots who have completed training and performed a successful Extraterrestrial life is Life originating outside of the Earth. Intergalactic space is the physical space between galaxies. Generally free of dust and debris intergalactic space is very close to a total Vacuum. The Interplanetary Internet, as presently conceived is a set of floating nodes in space which can communicate with each other The National Aeronautics and Space Administration ( NASA, ˈnæsə is an agency of the United States government, responsible for the nation's public space program Key points of the Treaty The Outer Space Treaty represents the basic legal framework of international space law Private spaceflight is flight above Earth Altitude conducted by and paid for by an entity other than a government The solar wind is a Stream of charged particles&mdasha plasma &mdashthat are ejected from the upper atmosphere of the Sun. Space and survival is the relationship between Outer space and the long-term Survival of the Human species and Civilization. Space colonization (also called space settlement, space humanization, Space habitation, etc History First orbital flights The first successful orbital launch was of the Soviet unmanned Sputnik Space science is an all-encompassing term that describes all of the various science fields that are concerned with the study of the Universe, generally also meaning "excluding A space station is an artificial structure designed for Humans to live in Outer space. Space technology is Technology that is related to entering space, maintaining and using systems during Spaceflight and returning people and things Spaceflight is the use of Space technology to fly a Spacecraft into and through Outer space. This is a timeline of known Spaceflights, both manned and unmanned sorted chronologically by launch date Retrieved on 2008-03-24. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 1401 - Mongol emperor Timur sacks Damascus. 1603 - James VI of Scotland
  2. ^ Etymonline: Space. Retrieved on 2008-03-24. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 1401 - Mongol emperor Timur sacks Damascus. 1603 - James VI of Scotland
  3. ^ NASA Human Body in a Vacuum
  4. ^ a b c d e Harding, Richard M. (1989), Survival in Space: Medical Problems of Manned Spaceflight, London: Routledge, ISBN 0-415-00253-2 .
  5. ^ Billings, Charles E. (1973). "Barometric Pressure", in edited by James F. Parker and Vita R. West: Bioastronautics Data Book, Second Edition, NASA. NASA SP-3006.  
  6. ^ Human Exposure to Vacuum. Retrieved on 2006-03-25. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 1199 - Richard I is wounded by a crossbow bolt while fighting France which leads to his death on April 6.
  7. ^ Webb P. (1968). "The Space Activity Suit: An Elastic Leotard for Extravehicular Activity". Aerospace Medicine 39: 376–383.  
  8. ^ Czarnik, Tamarack R. . EBULLISM AT 1 MILLION FEET: Surviving Rapid/Explosive Decompression. Retrieved on 2006-03-25. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 1199 - Richard I is wounded by a crossbow bolt while fighting France which leads to his death on April 6.
  9. ^ Linda Shiner. X-15 Walkaround: A short guide to the fastest airplane ever.. Air & Space Magazine. Retrieved on 2007-01-19. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 1419 - Hundred Years' War: Rouen surrenders to Henry V of England completing his reconquest of Normandy.
  10. ^ Report of the Living With a Star Geospace Mission Definition Team. NASA (September, 2002).
  11. ^ LWS Geospace Missions. NASA.
  12. ^ Davidson, Keay & Smoot, George. Wrinkles in Time. New York: Avon, 1993: 158-163
  13. ^ Silk, Joseph. Big Bang. New York: Freeman, 1977: 299.
  14. ^ NASA COBE website[1]
  15. ^ FAR 91. 211, http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgFAR.nsf/0/ba9afbf96dbc56f0852566cf006798f9!OpenDocument&ExpandSection=-3

External links

Dictionary

outer space

-noun

  1. Region outside explored space.
  2. Any region of space beyond limits determined with reference to boundaries of a celestial system or body, especially the region of space immediately beyond Earth's atmosphere
  3. (colour) A slightly lighter black color
© 2009 citizendia.org; parts available under the terms of GNU Free Documentation License, from http://en.wikipedia.org
 Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic