Portal:Outer space
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Introduction
Outer space (or simply space) is the expanse beyond celestial bodies and their atmospheres. 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
Ceres is the smallest identified dwarf planet in the Solar System and the only one in the asteroid belt. It was discovered on 1 January 1801, by Giuseppe Piazzi, and for half a century it was classified as the eighth planet. It is named after Ceres, the Roman goddess of growing plants, the harvest, and motherly love. With a diameter of about 950 km (590 miles), Ceres is by far the largest and most massive body in the asteroid belt, and contains a third (32%) of the belt's total mass. Recent observations have revealed that it is spherical, unlike the irregular shapes of smaller bodies with lower gravity. The surface of Ceres is probably made of a mixture of water ice and various hydrated minerals like carbonates and clays. Ceres appears to be differentiated into a rocky core and ice mantle. It may harbour an ocean of liquid water underneath its surface. From the Earth, Ceres' apparent magnitude ranges from 6.7 to 9.3, and hence at its brightest it is still too dim to be seen with the naked eye. The unmanned Dawnspacecraft, launched on 27 September 2007 by NASA, is expected to be the first to explore Ceres after its scheduled arrival there in 2015.
Selected picture
- Image 1Pale Blue Dot is the name given to this 1990 photo of Earth taken from Voyager 1 when its vantage point reached the edge of the Solar System, a distance of roughly 3.7 billion miles (6 billion kilometres). Earth can be seen as a blueish-white speck approximately halfway down the brown band to the right. The light band over Earth is an artifact of sunlight scattering in the camera's lens, resulting from the small angle between Earth and the Sun. Carl Sagan came up with the idea of turning the spacecraft around to take a composite image of the Solar System. Six years later, he reflected, "All of human history has happened on that tiny pixel, which is our only home."
- Image 2Photo credit: Spitzer Space TelescopeThis 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.
- Image 3A 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.
- Image 4NGC 4414 is an unbarred spiral galaxy about 62 million light-years away in the constellation Coma Berenices. It is a flocculent spiral galaxy, with short segments of spiral structure but without the dramatic well-defined spiral arms of a grand design spiral. NGC 4414 is a very isolated galaxy, with no signs of past interactions with other galaxies.
- Image 5Photograph: Ken CrawfordNGC 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.
- Image 6Photo: NASA/Crew of Expedition 22Space 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.
- Image 7NASA 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.
- Image 8"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.
- Image 9A 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.
- Image 10Six 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.
- Image 11Photograph: NASA, ESA, A. Aloisi (STScI/ESA), and The Hubble Heritage (STScI/AURA)-ESA/Hubble CollaborationAn 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.
- Image 12The 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.
- Image 13The Day the Earth Smiled refers to the date July 19, 2013, on which the Cassini spacecraft turned to image Saturn, its entire ring system, and the Earth from a position where Saturn eclipsed the Sun. Cassini imaging team leader and planetary scientist Carolyn Porco called for all the world's people to reflect on humanity's place in the cosmos, to marvel at life on Earth, and to look up and smile in celebration. The final mosaic, shown here, was released four months later and includes planets Earth, Mars, and Venus, and a host of Saturnian moons.
- Image 14Photo credit: New Horizons probeAn 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.
- Image 15Photograph: NASA/JPL-Caltech/University of ArizonaThe Helix Nebula is a large planetary nebula located in the constellation Aquarius. Discovered by Karl Ludwig Harding, probably before 1824, it is one of the closest to Earth of all the bright planetary nebulae, about 215 parsecs (700 light-years) away. It is similar in appearance to the Cat's Eye Nebula and the Ring Nebula.
- Image 16Photo credit: Spirit roverA 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.
- Image 17Photo credit: Harrison SchmittAstronaut 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.
- Image 18Map credit: Ignace-Gaston PardiesIgnace-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.
- Image 19The 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.
- Image 20Extra-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).
- Image 21Uranus is the seventh planet from the Sun and the fourth most massive in the Solar System. In this photograph from 1986 the planet appears almost featureless, but recent terrestrial observations have found seasonal changes to be occurring.
- Image 22Credit: NASA, ESA, AURA/Caltech, Palomar ObservatoryThe 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.
Space-related portals
General images
- Image 1Because of the hazards of a vacuum, astronauts must wear a pressurized space suit while outside their spacecraft.
- Image 2Astronaut Piers Sellers during the third spacewalk of STS-121, a demonstration of orbiter heat shield repair techniques (from Outline of space science)
- Image 3Earth and the Moon as seen from cislunar space on the 2022 Artemis 1 mission (from Outer space)
- Image 4Space 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)
- Image 6Voyager 1 is the first artificial object to reach the interstellar medium. (from Interstellar medium)
- Image 8Near-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)
- Image 11Saudi officials inspect a crashed PAM-D module in January 2001. (from Space debris)
- Image 12Astronaut Buzz Aldrin had a personal Communion service when he first arrived on the surface of the Moon. (from Space exploration)
- Image 13Large-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)
- Image 14Growth 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)
- Image 16A proposed timeline of the origin of space, from physical cosmology (from Outline of space science)
- Image 17The 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) harv error: no target: CITEREFHaffnerReynoldsTufteMadsen2003 (help). (from Interstellar medium)
- Image 18A laser-guided observation of the Milky Way Galaxy at the Paranal Observatory in Chile in 2010 (from Outline of space science)
- Image 19Debris 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)
- Image 20Spatial density of space debris by altitude according to ESA MASTER-2001, without debris from the Chinese ASAT and 2009 collision events (from Space debris)
- Image 21Objects in Earth orbit including fragmentation debris, November 2020, NASA: ODPO (from Space debris)
- Image 22Outer 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)
- Image 23Astronomers 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)
- Image 25Spent upper stage of a Delta II rocket, photographed by the XSS 10 satellite (from Space debris)
- Image 26Spatial 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)
- Image 27Atmospheric 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)
- Image 28A dusty trail from the early Solar System to carbonaceous dust today. (from Cosmic dust)
- Image 29First television image of Earth from space, taken by TIROS-1 (1960) (from Space exploration)
- Image 30A MESSENGER image from 18,000 km showing a region about 500 km across (2008) (from Space exploration)
- Image 31Major elements of 200 stratospheric interplanetary dust particles. (from Cosmic dust)
- Image 33Timeline of the expansion of the universe, where space, including hypothetical non-observable portions of the universe, is represented at each time by the circular sections. On the left, the dramatic expansion occurs in the inflationary epoch; and at the center, the expansion accelerates (artist's concept; neither time nor size are to scale). (from Outer space)
- Image 34Artistic image of a rocket lifting from a Saturn moon (from Space exploration)
- Image 35The Long Duration Exposure Facility (LDEF) is an important source of information on small-particle space debris. (from Space debris)
- Image 36Smooth chondrite interplanetary dust particle. (from Cosmic dust)
- Image 37Artist's impression of dust formation around a supernova explosion. (from Cosmic dust)
- Image 38Cosmic dust of the Andromeda Galaxy as revealed in infrared light by the Spitzer Space Telescope. (from Cosmic dust)
- Image 39Model of Vostok spacecraft (from Space exploration)
- Image 41Conventional anti-satellite weapons such as the SM-3 missile remain legal under space law, even though they create hazardous space debris (from Outer space)
- Image 42The original Magdeburg hemispheres (left) used to demonstrate Otto von Guericke's vacuum pump (right)
- Image 44Infographic showing the space debris situation in different kinds of orbits around Earth (from Space debris)
- Image 45Cosmic dust of the Horsehead Nebula as revealed by the Hubble Space Telescope. (from Cosmic dust)
- Image 46A view of the boundary between outer space and Earth, roughly where the yellow-green line of airglow is visible, at an altitude of 100 km, as viewed from the International Space Station (ISS) in low Earth orbit (LEO). (from Outer space)
- Image 47The diversity found in the different types and scales of astronomical objects make the field of study increasingly specialized. (from Outline of space science)
- Image 48A micrometeoroid left this crater on the surface of Space Shuttle Challenger's front window on STS-7. (from Space debris)
- Image 51Apollo CSM in lunar orbit (from Space exploration)
- Image 52Debris density in low Earth orbit (from Space debris)
- Image 54The 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.
- Image 55Reconstruction of solar activity over 11,400 years. Period of equally high activity over 8,000 years ago marked. (from Space climate)
- Image 56The black background is outer space as seen from Earth's surface at night. The interplanetary dust cloud is 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)
- Image 57Vanguard 1 is expected to remain in orbit for 240 years. (from Space debris)
- Image 58Apollo 16 LEM Orion, the Lunar Roving Vehicle and astronaut John Young (1972) (from Space exploration)
- Image 59A computer-generated map of objects orbiting Earth, as of 2005. About 95% are debris, not working artificial satellites (from Outer space)
- Image 60Known orbit planes of Fengyun-1C debris one month after the weather satellite's disintegration by the Chinese ASAT (from Space debris)
- Image 61Buzz Aldrin taking a core sample of the Moon during the Apollo 11 mission (from Space exploration)
- Image 62Concept art for a NASA Vision mission (from Space exploration)
- Image 64For 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)
- Image 66This light-year-long knot of interstellar gas and dust resembles a caterpillar. (from Interstellar medium)
- Image 67Gabbard 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)
- Image 70Bow shock formed by the magnetosphere of the young star LL Orionis (center) as it collides with the Orion Nebula flow
- Image 71Perseverance's backshell sitting upright on the surface of Jezero Crater (from Space debris)
- Image 72Illustration of Earth's atmosphere gradual transition into outer space (from Outer space)
- Image 73Map 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)
Did you know (auto-generated)
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- ... 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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