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.

Outer space (or simply space) is the expanse that exists beyond Earth's atmosphere and between celestial bodies. It contains ultra-low levels of particle densities, constituting a near-perfect vacuum of predominantly hydrogen and helium plasma, permeated by electromagnetic radiation, cosmic rays, neutrinos, magnetic fields and dust. 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.

The concept that the space between the Earth and the Moon must be a vacuum was first proposed in the 17th century after scientists discovered that air pressure decreased with altitude. The immense scale of outer space was grasped in the 20th century when the distance to the Andromeda Galaxy was first measured. Humans began the physical exploration of space later in the same 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

Titan is the largest moon of Saturn, the only natural satellite known to have a dense atmosphere, and the only object other than Earth for which clear evidence of stable bodies of surface liquid has been found. Discovered on 25 March 1655 by the Dutch astronomer Christiaan Huygens, Titan is the sixth ellipsoidal moon from Saturn. Frequently described as a planet-like moon, it is the second-largest natural satellite in the Solar System, after Jupiter's moon Ganymede, and it is larger by volume than the smallest planet, Mercury. Titan itself is primarily composed of water ice and rocky material. Its dense, opaque atmosphere meant that little was known of the surface features or conditions until the Cassini–Huygens mission in 2004. Although mountains and several possible cryovolcanoes have been discovered, its surface is relatively smooth and few impact craters have been found. Owing to the existence of stable bodies of surface liquids and its thick nitrogen-based atmosphere, Titan has been cited as a possible host for microbial extraterrestrial life or, at least, as a prebiotic environment rich in complex organic chemistry.

Selected picture

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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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  STS-116

  Photo credit: NASA

  NASA astronaut Robert Curbeam (left) and European Space Agency (ESA) astronaut Christer Fuglesang participate in STS-116's first of three planned sessions of extra-vehicular activity (EVA) as construction resumes on the International Space Station. The landmasses depicted in the background are the South Island (left) and North Island (right) of New Zealand.
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  Tvashtar Paterae

  Photo credit: New Horizons probe

  An animation of an eruption by the Tvashtar Paterae volcanic region on the innermost of Jupiter's Galilean moons, Io. The ejecta plume is 330 km (205 mi) high, though only its uppermost half is visible in this image, as its source lies over the moon's limb on its far side. This animation consists of a sequence of five images taken by NASA's New Horizons probe on March 1, 2007, over the course of eight minutes from 23:50 UTC.
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  Europa (moon)

  Photo credit: NASA/JPL

  Realistic-color mosaic of images of Jupiter's moon Europa taken by NASA's Jupiter orbiter Galileo in 1995 and 1998. This view of the moon's anti-Jovian hemisphere shows numerous lineae, linear features created via a tectonic process in which crustal plates of water ice floating on a subsurface ocean (kept warm by tidal flexing) shift in relative position. Reddish regions are areas where the ice has a higher mineral content. The north polar region is at right. (Geologic features are annotated in Commons.)
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  Kepler's Supernova

  Supernova remnant

  Credit: NASA

  This Supernova remnant of Kepler's Supernova (SN 1604) is made up of the materials left behind by the gigantic explosion of a star. There are two possible routes to this end: either a massive star may cease to generate fusion energy in its core, and collapse inward under the force of its own gravity, or a white dwarf star may accumulate material from a companion star until it reaches a critical mass and undergoes a similar collapse. In either case, the resulting supernova explosion expels much or all of the stellar material with great force.

  
  
  
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  Pillars of Creation

  Photograph: NASA, ESA, and the Hubble Heritage Team

  The Pillars of Creation, a series of elephant trunks of interstellar gas and dust in the Eagle Nebula, are the subject of a famous Hubble Space Telescope photograph taken in 1995. They are so named because the depicted gas and dust, while being eroded by the light from nearby stars, are in the process of creating new stars. Shown here is a 2014 rephotograph, which was unveiled in 2015 as part of the telescope's 25th anniversary celebrations.
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  STS-1

  Photo credit: NASA

  A timed exposure of the first Space Shuttle mission, STS-1. The shuttle Columbia stands on launch pad A at Kennedy Space Center, the night before launch. The objectives of the maiden flight were to check out the overall Shuttle system, accomplish a safe ascent into orbit and to return to Earth for a safe landing.
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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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  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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  Lunar phase

  Image: Tom Ruen

  An animation of the phases of the Moon. As the Moon revolves around the Earth, the Sun lights the Moon from a different side, creating the different phases. In the image, the Moon appears to get bigger as well as "wobble" slightly. Tidal locking synchronizes the Moon's rotation period on its axis to match its orbital period around the earth. These two periods nearly cancel each other out, except that the Moon's orbit is elliptical. This causes its orbital motion to speed up when closer to the Earth, and slow down when farther away, causing the Moon's apparent diameter to change, as well as the wobbling motion observed.
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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.
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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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  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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  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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  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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  Sombrero Galaxy

  Sombrero Galaxy M104

  Credit: NASA / STScI

  The Sombrero Galaxy is a spiral galaxy in the Virgo constellation. It was discovered in the late 1700s. It is about 28 million light years away and is just faint enough to be invisible to the naked eye but easily visible with small telescopes. In our sky, it is about one-fifth the diameter of the full moon. M104 is moving away from Earth at about 1,000 kilometers per second.

  
  
  
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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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  TRACE image of sunspots

  Sunspot

  Credit: NASA/TRACE

  A TRACE image of sunspots on the surface, or photosphere, of the sun from September 2002, is taken in the far ultraviolet on a relatively quiet day for solar activity. However, the image still shows a large sunspot group visible as a bright area near the horizon. Although sunspots are relatively cool regions on the surface of the sun, the bright glowing gas flowing around the sunspots have a temperature of over one million °C (1.8 million °F). The high temperatures are thought to be related to the rapidly changing magnetic field loops that channel solar plasma.
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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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  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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  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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  Solar flare

  Photo: Goddard Space Flight Center

  A solar flare, a sudden flash of brightness observed over the Sun's surface or the solar limb which is interpreted as a large energy release, recorded on August 31, 2012. Such flares are often, but not always, followed by a colossal coronal mass ejection; in this instance, the ejection traveled at over 900 miles (1,400 km) per second.

Space-related portals

General images

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

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  Model of Vostok spacecraft (from Space exploration)
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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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  A dusty trail from the early Solar System to carbonaceous dust today. (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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  The original Magdeburg hemispheres (left) used to demonstrate Otto von Guericke's vacuum pump (right)
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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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  Objects in Earth orbit including fragmentation debris, November 2020, NASA: ODPO (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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  The Long Duration Exposure Facility (LDEF) is an important source of information on small-particle space debris. (from Space debris)
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  Self-portrait of Curiosity rover on Mars's surface (from Space exploration)
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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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  Perseverance's backshell sitting upright on the surface of Jezero Crater (from Space debris)
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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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  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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  Conventional anti-satellite weapons such as the SM-3 missile remain legal under the law of armed conflict, even though they create hazardous space debris (from Outer space)
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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 for a space-based solar power system to beam energy down to Earth (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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  Illustration of Earth's atmosphere gradual transition into outer space (from Outer space)
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  NASA computer-generated image of debris objects in Earth orbit, c. 2005 (from Space debris)
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  Large-scale matter distribution in a cubic section of the universe. The blue fiber-like 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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  Porous chondrite dust particle (from Cosmic dust)
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  View of an orbital debris hole made in the panel of the Solar Max satellite (from Space debris)
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  Smooth chondrite interplanetary dust particle. (from Cosmic dust)
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  Surface of Mars by the Spirit rover (2004) (from Space exploration)
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  Voyager 1 is the first artificial object to reach the interstellar medium. (from Interstellar medium)
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  Debris density in low Earth orbit (from Space debris)
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  Major elements of 200 stratospheric interplanetary dust particles. (from Cosmic dust)
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  Cosmic dust of the Horsehead Nebula as revealed by the Hubble Space Telescope. (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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  Space debris identified as WT1190F, burning up in a fireball over Sri Lanka (from Space debris)
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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 z ≈ 7, 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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  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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  V-2 Rocket in the Peenemünde Museum (from Space exploration)
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  Near-Earth space showing the low-Earth (blue), medium Earth (green), and high Earth (red) orbits. The last extends beyond the radius of geosynchronous orbits (from Outer space)
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  This light-year-long knot of interstellar gas and dust resembles a caterpillar. (from Interstellar medium)
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  After reentry, Delta 2 second stage pieces were found in South Africa. (from Space debris)
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  Delta-v's in km/s for various orbital maneuvers (from Space exploration)
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  The International Space Station is an orbiting laboratory for space applications and habitability. Visible in the background is yellow-green airglow of Earth's ionosphere and the interstellar field of the Milky Way. (from Outer space)
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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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  Spent upper stage of a Delta II rocket, photographed by the XSS 10 satellite (from Space debris)
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  Baker-Nunn cameras were widely used to study space debris. (from Space debris)
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  South is up in the first image of Earth taken by a person, probably by Bill Anders (during the 1968 Apollo 8 mission) (from Outer space)
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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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  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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  Infographic showing the space debris situation in different kinds of orbits around Earth (from Space debris)
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  Apollo Command Service Module in lunar orbit (from Space exploration)
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  Tupan Patera on Jupiter's moon Io (from Space exploration)
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  Illustration of a satellite breaking up into multiple pieces at higher altitudes (from Space debris)
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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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  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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  Asteroid 4 Vesta, imaged by the Dawn spacecraft (2011) (from Space exploration)
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  First television image of Earth from space, taken by TIROS-1 (1960) (from Space exploration)
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  Crew quarters on Zvezda, the base ISS crew module (from Space exploration)
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  Zodiacal light caused by cosmic dust. (from Cosmic dust)
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  Concept art for a NASA Vision mission (from Space exploration)
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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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  A drifting thermal blanket photographed in 1998 during STS-88 (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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  Herbig–Haro object HH 110 ejects gas through interstellar space. (from Interstellar medium)
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  Three-dimensional structure in Pillars of Creation. (from Interstellar medium)
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  Artist's impression of dust formation around a supernova explosion. (from Cosmic dust)
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  A proposed timeline of the origin of space, from physical cosmology (from Outline of space science)
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  A wide field view of outer space as seen from Earth's surface at night. The interplanetary dust cloud is visible as the horizontal band of zodiacal light, including the false dawn (edges) and gegenschein (center), which is visually crossed by the Milky Way (from Outer space)
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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 micrometeoroid left this crater on the surface of Space Shuttle Challenger's front window on STS-7. (from Space debris)
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  Saudi officials inspect a crashed PAM-D module in January 2001. (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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  A computer-generated animation by the European Space Agency representing space debris in low earth orbit at the current rate of growth compared to mitigation measures being taken (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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  Timeline of the expansion of the universe, where visible space is represented by the circular sections. At left, a dramatic expansion occurs in the inflationary epoch, and at the center, the expansion accelerates. Neither time nor size are to scale. (from Outer space)
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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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  Comet 103P/Hartley (2010) (from Space exploration)
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  Interstellar medium and astrosphere meeting (from Interstellar medium)
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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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  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 computer-generated map of objects orbiting Earth, as of 2005. About 95% are debris, not working artificial satellites (from Outer space)
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  Because of the hazards of a vacuum, astronauts must wear a pressurized space suit while outside their spacecraft.

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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