Portal:Outer space

The Outer space Portal

Introduction

Because of the hazards of a vacuum, astronauts must wear a pressurized space suit while off-Earth and outside their spacecraft.

The interface between Earth's surface and outer space. The Kármán line at an altitude of 100 km (62 mi) is shown. The layers of the atmosphere are drawn to scale, whereas objects within them, such as the International Space Station, are not.

Outer space, commonly referred to simply as space, is the expanse that exists beyond Earth and its atmosphere and between celestial bodies. Outer space is not completely empty; it is a near-perfect vacuum containing a low density of particles, predominantly a plasma of hydrogen and helium as well as electromagnetic radiation, magnetic fields, neutrinos, dust, and cosmic rays. The baseline temperature of outer space, as set by the background radiation from the Big Bang, is 2.7 kelvins (−270 °C; −455 °F).

The plasma between galaxies is thought to account for about half of the baryonic (ordinary) matter in the universe, having a number density of less than one hydrogen atom per cubic metre and a kinetic temperature of millions of kelvins. Local concentrations of matter have condensed into stars and galaxies. Intergalactic space takes up most of the volume of the universe, but even galaxies and star systems consist almost entirely of empty space. Most of the remaining mass-energy in the observable universe is made up of an unknown form, dubbed dark matter and dark energy.

Outer space does not begin at a definite altitude above Earth's surface. The Kármán line, an altitude of 100 km (62 mi) above sea level, is conventionally used as the start of outer space in space treaties and for aerospace records keeping. Certain portions of the upper stratosphere and the mesosphere are sometimes referred to as "near space". The framework for international space law was established by the Outer Space Treaty, which entered into force on 10 October 1967. This treaty precludes any claims of national sovereignty and permits all states to freely explore outer space. Despite the drafting of UN resolutions for the peaceful uses of outer space, anti-satellite weapons have been tested in Earth orbit.

Humans began the physical exploration of space during the 20th century with the advent of high-altitude balloon flights. This was followed by crewed rocket flights and, then, crewed Earth orbit, first achieved by Yuri Gagarin of the Soviet Union in 1961. The economic cost of putting objects, including humans, into space is very high, limiting human spaceflight to low Earth orbit and the Moon. On the other hand, uncrewed spacecraft have reached all of the known planets in the Solar System. Outer space represents a challenging environment for human exploration because of the hazards of vacuum and radiation. Microgravity has a negative effect on human physiology that causes both muscle atrophy and bone loss. (Full article...)

Selected article

Mars is the fourth planet from the Sun and is known as the Red Planet due to its reddish appearance as seen from Earth. The planet is named after Mars, the Roman god of war. A terrestrial planet, Mars has a thin atmosphere and surface features reminiscent both of the impact craters of the Moon and the volcanoes, valleys, deserts and polar ice caps of Earth. It has the highest mountain in the Solar System, Olympus Mons, and the largest canyon, Valles Marineris. Mars' rotational period and seasonal cycles are also similar to those of the Earth. Of all the planets in the Solar System other than Earth, Mars is the most likely to harbor liquid water, and perhaps life. Mars is currently host to three functional orbiting spacecraft: Mars Odyssey, Mars Express, and Mars Reconnaissance Orbiter. This is more than any planet except Earth. The surface is also home to the two Mars Exploration Rovers (Spirit and Opportunity). Geological evidence gathered by these and preceding missions suggests that Mars previously had large-scale water coverage, while observations also indicate that small geyser-like water flows have occurred in recent years. Mars has two moons, Phobos and Deimos, which are small and irregularly shaped.

Selected picture

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  Pioneer plaque

  Pioneer plaque

  Credit: Carl Sagan, Frank Drake, Linda Salzman Sagan

  The Pioneer plaque, which was included on both Pioneer 10 and Pioneer 11 unmanned spacecraft, the first man-made objects to leave the Solar System. Made from gold-anodised aluminium, the plaque shows the figures of a man and a woman along with several symbols that are designed to provide information about the origin of the spacecraft. However, the mean time for the spacecraft to come within 30 astronomical units of a star is longer than the current age of our galaxy.
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  Jupiter

  Image credit: NASA

  An animated view of Voyager I's approach to Jupiter. One frame of this image was taken each Jupiter day (approximately 10 hours) between January 6 and February 9, 1979, as the space probe flew from 58 million to 31 million kilometers from Jupiter during that time. The small, round, dark spots appearing in some frames are the shadows cast by the moons passing between Jupiter and the Sun, while the small, white flashes around the planet, are the moons themselves.
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  Lunar rover

  Photo credit: Harrison Schmitt

  Astronaut Eugene Cernan makes a short test drive of the lunar rover (officially, Lunar Roving Vehicle or LRV) during the early part of the first Apollo 17 extravehicular activity. The LRV was only used in the last three Apollo missions, but it performed without any major problems and allowed the astronauts to cover far more ground than in previous missions. All three LRVs were abandoned on the Moon.
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  Mercury (planet)

  Photograph: NASA/APL/CIS; edit: Jjron

  Mercury is the smallest and closest to the Sun of the eight planets in the Solar System. It has no known natural satellites. The planet is named after the Roman deity Mercury, the messenger to the gods.
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  Husband Hill

  Photo credit: Spirit rover

  A 360° panorama taken during the descent from the summit of Husband Hill, one of the Columbia Hills in Gusev crater, Mars. This stitched image is composed of 405 individual images taken with five different filters on the panoramic camera over the course of five Martian days.
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  Andromeda Galaxy

  Photo: Adam Evans

  The Andromeda Galaxy is a spiral galaxy approximately 2.5 million light-years away. The image, created using a hydrogen-alpha filter, also shows Messier objects 32 and 110, as well as NGC 206 and the star Nu Andromedae. On December 15, 1612, German astronomer Simon Marius became the first person to describe the galaxy using a telescope.
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  Color-composite image of the Pleiades from the Digitized Sky Survey

  Pleiades (star cluster)

  Credit: NASA, ESA, AURA/Caltech, Palomar Observatory

  The Pleiades (also known as M45 or the Seven Sisters) is an open cluster in the constellation of Taurus. It is among the nearest to the Earth of all open clusters, probably the best known and certainly the most striking to the naked eye.

  
  
  
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  Needle Galaxy

  Photograph: Ken Crawford

  NGC 4565 (also known as the Needle Galaxy) is an edge-on spiral galaxy about 30 to 50 million light-years away in the constellation Coma Berenices. NGC 4565 is a giant spiral galaxy more luminous than the Andromeda Galaxy, and has a population of roughly 240 globular clusters, more than the Milky Way.
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  Geostationary orbit

  Animation credit: Cmglee

  This is an animation showing geocentric satellite orbits, to scale with the Earth, at 3,600 times actual speed. The second-outermost (shown in grey) is a geostationary orbit, 35,786 kilometres (22,236 miles) above Earth's equator and following the direction of Earth's rotation, with an orbital period matching the planet's rotation period (a geosynchronous orbit). An object in such an orbit will appear to occupy a fixed position in the sky. Some 300 kilometres (190 miles) farther away is the graveyard orbit (brown), used for satellites at the end of their operational lives. Nearer to the Earth are the orbits of navigational satellites, such as Galileo (turquoise), BeiDou (beige), GPS (blue) and GLONASS (red), in medium Earth orbits. Much closer to the planet, and within the inner Van Allen belt, are satellites in low Earth orbit, such as the Iridium satellite constellation (purple), the Hubble Space Telescope (green) and the International Space Station (magenta).
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  Retrograde and direct motion

  Image credit: Seav

  An animated image showing the apparent retrograde motion of Mars in 2003 as seen from Earth. All the true planets appear to periodically switch direction as they cross the sky. Because Earth completes its orbit in a shorter period of time than the planets outside its orbit, we periodically overtake them, like a faster car on a multi-lane highway. When this occurs, the planet will first appear to stop its eastward drift, and then drift back toward the west. Then, as Earth swings past the planet in its orbit, it appears to resume its normal motion west to east.
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  Earth

  The Blue Marble

  Credit: The Apollo 17 crew

  "The Blue Marble" is a famous photograph of Earth. NASA officially credits the image to the entire Apollo 17 crew — Eugene Cernan, Ronald Evans and Jack Schmitt — all of whom took photographic images during the mission. Apollo 17 passed over Africa during daylight hours and Antarctica is also illuminated. The photograph was taken approximately five hours after the spacecraft's launch, while en route to the Moon. Apollo 17, notably, was the last manned lunar mission; no humans since have been at a range where taking a "whole-Earth" photograph such as "The Blue Marble" would be possible.
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  Milky Way

  Photo credit: Spitzer Space Telescope

  This infrared image shows hundreds of thousands of stars crowded into the swirling core of our spiral Milky Way galaxy. In visible-light pictures, this region cannot be seen at all because cosmic dust lying between Earth and the galactic center blocks our view.
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  Space Shuttle Atlantis launch plume

  Space Shuttle program

  Credit: NASA/Fir0002

  The launch of Space Shuttle Atlantis on STS-98, February 7 2001, at sunset. The sun is behind the camera, and the shape of the plume is cast across the vault of the sky, intersecting the rising full moon. The top portion of the plume is bright because it is illuminated directly by the sun; the lower portions are in the Earth's shadow. After launch, the shuttle must engage in a pitch and roll program so that the vehicle is below the external tank and SRBs, as evidenced in the plume trail. The vehicle climbs in a progressively flattening arc, because achieving low orbit requires much more horizontal than vertical acceleration.

  
  
  
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  Jupiter

  Diagram: Kelvin Song

  A diagram of Jupiter showing a model of the planet's interior, with a rocky core overlaid by a deep layer of liquid metallic hydrogen and an outer layer predominantly of molecular hydrogen. Jupiter's true interior composition is uncertain. For instance, the core may have shrunk as convection currents of hot liquid metallic hydrogen mixed with the molten core and carried its contents to higher levels in the planetary interior. Furthermore, there is no clear physical boundary between the hydrogen layers—with increasing depth the gas increases smoothly in temperature and density, ultimately becoming liquid.
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  Space Shuttle Endeavour

  Photo: NASA/Crew of Expedition 22

  Space Shuttle Endeavour in a photograph taken from the International Space Station, in which the shuttle appears to straddle the stratosphere and mesosphere. During this mission, STS-130, the shuttle's primary payloads were the Tranquility module and the Cupola, a robotic control station which provides a 360-degree view around the station.
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  Ignace-Gaston Pardies

  Map credit: Ignace-Gaston Pardies

  Ignace-Gaston Pardies (1636–1673) was a French Catholic priest and scientist. His celestial atlas, entitled Globi coelestis in tabulas planas redacti descriptio, comprised six charts of the night sky and was first published in 1674. The atlas uses a gnomonic projection so that the plates make up a cube of the celestial sphere. The constellation figures are drawn from Uranometria, but were carefully reworked and adapted to a broader view of the sky. This is the second plate from a 1693 edition of Pardies's atlas, featuring constellations including Pegasus and Andromeda, visible in the northern sky.
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  Astronaut Steve Robinson on a spacewalk, August 2005

  Extra-vehicular activity

  Credit: NASA

  Extra-vehicular activity (EVA) is work done by an astronaut away from the Earth and outside of his or her spacecraft. EVAs may be made outside a craft orbiting Earth (a spacewalk) or on the surface of the Moon (a moonwalk). Shown here is Steve Robinson on the first EVA to perform an in-flight repair of the Space Shuttle (August 3 2005).
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  James Webb Space Telescope

  Photo: NASA/MSFC/David Higginbotham/Emmett Given

  Six beryllium mirror segments of the James Webb Space Telescope (JWST) undergoing a series of cryogenic tests at NASA's Marshall Space Flight Center in Huntsville, Alabama. The JWST is a planned space telescope that is a joint collaboration of 20 countries. It will orbit the Sun approximately 1,500,000 km (930,000 mi) beyond the Earth, around the L₂ Lagrange point. It is expected to launch in December 2021.
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  433 Eros asteroid

  433 Eros

  Credit: NASA

  The asteroid 433 Eros was named after the Greek god of love Eros. This S-type asteroid is the second-largest near-Earth asteroid. This image shows the view looking from one end of the asteroid across the gouge on its underside and toward the opposite end.
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  Orion Nebula

  Orion Nebula

  Credit: Hubble Space Telescope

  A composite photo of the Orion Nebula, the closest region of star formation to Earth. It is composed of 520 separate images and NASA calls it "one of the most detailed astronomical images ever produced". The nebula is located below Orion's Belt and is visible to the naked eye at night. It is one of the most scrutinized and photographed objects in the night sky, and is among the most intensely-studied celestial features.
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  NGC 4449

  Photograph: NASA, ESA, A. Aloisi (STScI/ESA), and The Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration

  An image of NGC 4449, highlighting its qualities as a starburst galaxy. NGC 4449, an irregular galaxy in the constellation Canes Venatici located about 12 million light years from Earth, has a rate of star formation twice that of the Milky Way's satellite galaxy, the Large Magellanic Cloud. Interactions with nearby galaxies are thought to have influenced this star formation.
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  Cassini–Huygens

  Photograph credit: NASA / JPL / Space Science Institute

  The Cassini–Huygens space-research project involved a collaboration between NASA, the European Space Agency, and the Italian Space Agency to send a probe to study the planet Saturn and its system, including its rings and its natural satellites.
  
  This natural-color mosaic image, combining thirty photographs, was taken by the Cassini orbiter over the course of approximately two hours on 23 July 2008 as it panned its wide-angle camera across Saturn and its ring system as the planet approached equinox. Six moons are pictured in the panorama, with the largest, Titan, visible at the bottom left.

Space-related portals

General images

The following are images from various outer space-related articles on Wikipedia.

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  Herbig–Haro object HH 110 ejects gas through interstellar space. (from Interstellar medium)

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  Aurora australis observed from the International Space Station (from Outer space)

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  First television image of Earth from space, taken by TIROS-1. (1960) (from Space exploration)

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  Debris impacts on Mir's solar panels degraded their performance. The damage is most noticeable on the panel on the right, which is facing the camera with a high degree of contrast. Extensive damage to the smaller panel below is due to impact with a Progress spacecraft. (from Space debris)

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  Major elements of 200 stratospheric interplanetary dust particles. (from Cosmic dust)

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  Surface of Mars by the Spirit rover (2004) (from Space exploration)

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  A drifting thermal blanket photographed in 1998 during STS-88. (from Space debris)

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  The sparse plasma (blue) and dust (white) in the tail of comet Hale–Bopp are being shaped by pressure from solar radiation and the solar wind, respectively.

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  Self-portrait of Curiosity rover on Mars's surface (from Space exploration)

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  A computer-generated image representing the locations, but not relative sizes, of space debris as could be seen from high Earth orbit (HEO). The two main debris fields are the ring of objects in geosynchronous Earth orbit (GEO) and the cloud of objects in low Earth orbit (LEO). (from Space debris)

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  Asteroid 4 Vesta, imaged by the Dawn spacecraft (2011) (from Space exploration)

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  Bow shock formed by the magnetosphere of the young star LL Orionis (center) as it collides with the Orion Nebula flow

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  Spatial density of space debris by altitude according to ESA MASTER-2001, without debris from the Chinese ASAT and 2009 collision events (from Space debris)

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  Spatial density of LEO space debris by altitude, according to 2011 a NASA report to the United Nations Office for Outer Space Affairs (from Space debris)

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  Zodiacal light caused by cosmic dust. (from Cosmic dust)

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  Baker-Nunn cameras were widely used to study space debris. (from Space debris)

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  Cosmic dust of the Horsehead Nebula as revealed by the Hubble Space Telescope. (from Cosmic dust)

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  Because of the hazards of a vacuum, astronauts must wear a pressurized space suit while off-Earth and outside their spacecraft.

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  Delta-v's in km/s for various orbital maneuvers (from Space exploration)

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  Atmospheric attenuation in dB/km as a function of frequency over the EHF band. Peaks in absorption at specific frequencies are a problem, due to atmosphere constituents such as water vapor (H₂O) and carbon dioxide (CO₂). (from Interstellar medium)

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  This is an artist's concept of the expansion of the universe, where a volume of the universe is represented at each time interval by the circular sections. At left is depicted the rapid inflation from the initial state, followed thereafter by steadier expansion to the present day, shown at right. (from Outer space)

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  Artist's impression of dust formation around a supernova explosion. (from Cosmic dust)

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  Comet 103P/Hartley (2010) (from Space exploration)

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  Spent upper stage of a Delta II rocket, photographed by the XSS 10 satellite (from Space debris)

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  Earth and the Moon as seen from cislunar space on the 2022 Artemis 1 mission (from Outer space)

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  Known orbit planes of Fengyun-1C debris one month after the weather satellite's disintegration by the Chinese ASAT (from Space debris)

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  The Long Duration Exposure Facility (LDEF) is an important source of information on small-particle space debris. (from Space debris)

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  Large-scale matter distribution in a cubic section of the universe. The blue fiber structures represent the matter and the empty regions in between represent the cosmic voids of the intergalactic medium (from Outer space)

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  Objects in Earth orbit including fragmentation debris. November 2020 NASA:ODPO (from Space debris)

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  Model of Vostok spacecraft (from Space exploration)

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  A micrometeoroid left this crater on the surface of Space Shuttle Challenger's front window on STS-7. (from Space debris)

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  The interface between Earth's surface and outer space. The Kármán line at an altitude of 100 km (62 mi) is shown. The layers of the atmosphere are drawn to scale, whereas objects within them, such as the International Space Station, are not. (from Outer space)

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  Astronaut Buzz Aldrin had a personal Communion service when he first arrived on the surface of the Moon. (from Space exploration)

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  Saudi officials inspect a crashed PAM-D module in January 2001. (from Space debris)

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  Astronaut Piers Sellers during the third spacewalk of STS-121, a demonstration of orbiter heat shield repair techniques (from Outline of space science)

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  For the first time, the NASA / ESA / Canadian Space Agency / James Webb Space Telescope has observed the chemical signature of carbon-rich dust grains at redshift, which is roughly equivalent to one billion years after the birth of the Universe, this observation suggests exciting avenues of investigation into both the production of cosmic dust and the earliest stellar populations in our Universe. (from Cosmic dust)

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  Voyager 1 is the first artificial object to reach the interstellar medium. (from Interstellar medium)

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  A proposed timeline of the origin of space, from physical cosmology (from Outline of space science)

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  SpaceShipOne completed the first human private spaceflight in 2004, reaching an altitude of 100.12 km (62.21 mi)

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  A computer-generated image mapping the prevalence of artificial satellites and space debris around Earth in geosynchronous and low Earth orbit (from Outer space)

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  The distribution of ionized hydrogen (known by astronomers as H II from old spectroscopic terminology) in the parts of the Galactic interstellar medium visible from the Earth's northern hemisphere as observed with the Wisconsin Hα Mapper (Haffner et al. 2003). (from Interstellar medium)

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  A dusty trail from the early Solar System to carbonaceous dust today. (from Cosmic dust)

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  Vanguard 1 is expected to remain in orbit for 240 years. (from Space debris)

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  Tupan Patera on Io (from Space exploration)

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  The first image taken by a human of the whole Earth, probably photographed by William Anders of Apollo 8 South is up; South America is in the middle. (from Outer space)

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  Satellite hit by a space debris; animation by ESA (from Space debris)

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  Orbit of 2020 SO (from Space debris)

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  The interplanetary dust cloud illuminated and visible as zodiacal light, with its parts the false dawn, gegenschein and the rest of its band, which is visually crossed by the Milky Way (from Outer space)

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  The diversity found in the different types and scales of astronomical objects make the field of study increasingly specialized. (from Outline of space science)

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  Crew quarters on Zvezda the base ISS crew module (from Space exploration)

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  Growth of tracked objects in orbit and related events; efforts to manage outer space global commons have so far not reduced the debris or the growth of objects in orbit (from Space debris)

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  A MESSENGER image from 18,000 km showing a region about 500 km across (2008) (from Space exploration)

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  Three-dimensional structure in Pillars of Creation. (from Interstellar medium)

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  2008 launch of the SM-3 missile used to destroy American reconnaissance satellite USA-193

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  Perseverance's backshell sitting upright on the surface of Jezero Crater (from Space debris)

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  Porous chondrite dust particle (from Cosmic dust)

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  Buzz Aldrin taking a core sample of the Moon during the Apollo 11 mission (from Space exploration)

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  A piece of a thermal blanket that may have come from the descent stage of the Perseverance (from Space debris)

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  Apollo CSM in lunar orbit (from Space exploration)

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  Smooth chondrite interplanetary dust particle. (from Cosmic dust)

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  V-2 Rocket in the Peenemünde Museum (from Space exploration)

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  Gabbard diagram of almost 300 pieces of debris from the disintegration of the five-month-old third stage of the Chinese Long March 4 booster on 11 March 2000 (from Space debris)

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  Reconstruction of solar activity over 11,400 years. Period of equally high activity over 8,000 years ago marked. (from Space climate)

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  The original Magdeburg hemispheres (lower left) used to demonstrate Otto von Guericke's vacuum pump (right)

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  A laser-guided observation of the Milky Way Galaxy at the Paranal Observatory in Chile in 2010 (from Outline of space science)

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  This light-year-long knot of interstellar gas and dust resembles a caterpillar. (from Interstellar medium)

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  Outer space from the International Space Station at 400 km (250 mi) altitude in low Earth orbit. In the background the Milky Way's interstellar space is visible, as well as in the foreground, above Earth, the airglow of the ionosphere just below and beyond the so-defined edge of space the Kármán line in the thermosphere (from Outer space)

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  Cosmic dust of the Andromeda Galaxy as revealed in infrared light by the Spitzer Space Telescope. (from Cosmic dust)

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  Apollo 16 LEM Orion, the Lunar Roving Vehicle and astronaut John Young (1972) (from Space exploration)

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  Map showing the Sun located near the edge of the Local Interstellar Cloud and Alpha Centauri about 4 light-years away in the neighboring G-Cloud complex (from Interstellar medium)

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  Artistic image of a rocket lifting from a Saturn moon (from Space exploration)

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  Concept art for a NASA Vision mission (from Space exploration)

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  Part of the Hubble Ultra-Deep Field image showing a typical section of space containing galaxies interspersed by deep vacuum. Given the finite speed of light, this view covers the past 13 billion years of the history of outer space.

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  Space Shuttle Endeavour had a major impact on its radiator during STS-118. The entry hole is about 5.5 mm (0.22 in), and the exit hole is twice as large. (from Space debris)

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  Astronomers used the James Webb Space Telescope to image the warm dust around a nearby young star, Fomalhaut, in order to study the first asteroid belt ever seen outside of the Solar System in infrared light. (from Cosmic dust)

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  Space Shuttle Discovery's lower starboard wing and Thermal Protection System tiles, photographed on STS-114 during an R-Bar Pitch Manoeuvre where astronauts examine the TPS for any damage during ascent (from Space debris)

Did you know (auto-generated)

• ... that, for the Space 220 Restaurant, Disney reached out to NASA engineers to understand what a space elevator might look like?
• ... that some severe environmental impacts of the invasion of Ukraine can be seen from space?
• ... that the space industry of India has supported the launch of more than 100 domestic satellites and more than 300 foreign satellites?
• ... that Nature's Fynd, producer of microbe-based meat substitutes, is working with NASA to develop a bioreactor for use in space travel?
• ... that Louis W. Roberts was among the highest ranking African-American space program staff at NASA while the Apollo program was underway?

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