Portal:Outer space
Introduction
Outer space, commonly shortened to 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 (−270.45 °C; −454.81 °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 temperature of millions of kelvins. Local concentrations of matter have condensed into stars and galaxies. Studies indicate that 90% of the mass in most galaxies is in an unknown form, called dark matter, which interacts with other matter through gravitational but not electromagnetic forces. Observations suggest that the majority of the mass-energy in the observable universe is dark energy, a type of vacuum energy that is poorly understood. Intergalactic space takes up most of the volume of the universe, but even galaxies and star systems consist almost entirely of empty space.
Outer space does not begin at a definite altitude above the 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. 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. Due to the high cost of getting into space, human spaceflight has been limited 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 also has a negative effect on human physiology that causes both muscle atrophy and bone loss. In addition to these health and environmental issues, the economic cost of putting objects, including humans, into space is very high. (Full article...)
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Pluto is the second-largest known dwarf planet in the Solar System and the tenth-largest body observed directly orbiting the Sun. Originally classified as the ninth planet from the Sun, Pluto was recategorized as a dwarf planet and plutoid owing to the discovery that it is only one of several large bodies within the Kuiper belt. Like other members of the belt, it is primarily composed of rock and ice and is relatively small; approximately a fifth the mass of the Earth's Moon and a third its volume. It has an eccentric orbit that takes it from 30 to 49 AU (4.4–7.4 billion km) from the Sun, and is highly inclined with respect to the planets. As a result, Pluto occasionally comes closer to the Sun than the planet Neptune. Pluto has five known moons, the largest being Charon, discovered in 1978, along with Nix and Hydra, discovered in 2005, and the provisionally named S/2011 (134340) 1, discovered in 2011, and S/2012 (134340) 1, discovered in 2012.
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Photograph credit: NASA / JPL / Space Science InstituteThe 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.
Credit: NASAA Manned Maneuvering Unit (MMU) is a jet pack (propulsion backpack that snaps onto the back of the space suit) which has been used on untethered spacewalks from NASA's Space Shuttle, allowing an astronaut to move independently from the shuttle. The MMU was used on three Shuttle missions in 1984. It was first tested on February 7 during mission STS-41-B by astronauts Bruce McCandless II (seen here) and Robert L. Stewart.
Photograph: 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.
Credit: NASAMars, the fourth planet from the Sun, is named after the Roman god of war because of its blood red color. Mars has two small, oddly-shaped moons, Phobos and Deimos, named after the sons of the Greek god Ares. At some point in the future Phobos will be broken up by gravitational forces. The atmosphere on Mars is 95% carbon dioxide. In 2003 methane was also discovered in the atmosphere. Since methane is an unstable gas, this indicates that there must be (or have been within the last few hundred years) a source of the gas on the planet.
Credit: NASAExtra-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 credit: Dave JarvisAn illustration of relative astronomical orders of magnitude, starting with the terrestrial planets of the Solar System in image 1 (top left) and ending with the largest known star, VY Canis Majoris, at the bottom right. The biggest celestial body in each image is shown on the left of the next frame.
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.
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.
Photo 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.- "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.
- 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.
Photo: 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.
Photo credit: Mars Reconnaissance OrbiterFalse-color Mars Reconnaissance Orbiter image of a side of the Chasma Boreale, a canyon in the polar ice cap of the Planum Boreum (north pole of Mars). Light browns are layers of surface dust, greys and blues are layers of water and carbon dioxide ice. Regular geometric cracking is indicative of higher concentrations of water ice.
The Planum Boreum's permanent ice cap has a maximum depth of 3 km (1.9 mi). It is roughly 1200 km (750 mi) in diameter, an area equivalent to about 1½ times the size of Texas. The Chasma Boreale is up to 100 km (62.5 mi) wide and features scarps up to 2 km (1.25 mi) high. For a comparison, the Grand Canyon is approximately 1.6 km (1 mi) deep in some places and 446 km (279 mi) long but only up to 24 km (15 mi) wide.
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.
Diagram: Kelvin SongA 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.
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.
Credit: NASAThis 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.
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.)
Credit: William Anders"Earthrise," the first occasion in which humans saw the Earth seemingly rising above the surface of the Moon, taken during the Apollo 8 mission on December 24, 1968. This view was seen by the crew at the beginning of its fourth orbit around the Moon, although the very first photograph taken was in black-and-white. Note that the Earth is in shadow here. A photo of a fully lit Earth would not be taken until the Apollo 17 mission.
Image credit: United States Geological SurveyA composite image of Olympus Mons on Mars, the tallest known volcano and mountain in the Solar System. This image was created from black-and-white imagery from the USGS's Mars Global Digital Image Mosaic and color imagery acquired from the 1978 visit of Viking 1.
Animation credit: CmgleeThis 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).
Photo: Yuri Beletsky, ESOA laser shoots towards the centre of the Milky Way from the Very Large Telescope facility in Chile, to provide a laser guide star, a reference point in the sky for the telescope's adaptive optics (AO) system. AO technology improves the performance of optical systems by reducing the effect of atmospheric distortion. AO was first envisioned by Horace W. Babcock in 1953, but did not come into common usage until advances in computer technology during the 1990s made the technique practical.
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Space news
- April 7: NASA's helicopter Ingenuity survives its first night at Mars
- December 25: 'Earth-based life can survive in hydrogen-rich atmospheres': MIT professor Dr Seager tells Wikinews about her research on organisms thriving in oxygen-less environment
- July 7: Astronomer Anthony Boccaletti discusses observation of birth of potential exoplanet with Wikinews
- May 31: SpaceX successfully launches its first crewed spaceflight
- May 22: Astronomer tells Wikinews about discovery of closest black hole known so far
- October 12: Cosmonaut Alexei Leonov dies at age 85
- October 10: Swedish academy announces 2019 Nobel Prize winners in physics
- September 14: Astronomers find water vapour in atmosphere of exoplanet K2-18b
- March 5: SpaceX Crew Dragon capsule docks with International Space Station
- January 9: Simple animals could live in Martian brines: Wikinews interviews planetary scientist Vlada Stamenković
- November 29: NASA's InSight Lander makes it to Mars
- October 12: Manned Soyuz space mission aborts during launch
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General images
New Horizons image of Pluto (2015) (from Space exploration)
A laser-guided observation of the Milky Way Galaxy at the Paranal Observatory in Chile in 2010 (from Outline of space science)
Ganymede (moon) (from Space exploration)
Reconstruction of solar activity over 11,400 years. Period of equally high activity over 8,000 years ago marked. (from Space climate)
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)
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)
Apollo 17 astronaut Harrison Schmitt standing next to a boulder at Taurus-Littrow. (from Space exploration)
Whirlpool Galaxy (Messier 51) (from Space exploration)
Self-portrait of Curiosity rover on Mars's surface (from Space exploration)
Herbig–Haro object HH 110 ejects gas through interstellar space. (from Interstellar medium)
Artist's impression of dust formation around a supernova explosion. (from Cosmic dust)
Porous chondrite interplanetary dust particle. (from Cosmic dust)
Major elements of 200 stratospheric interplanetary dust particles. (from Cosmic dust)
In July 1950 the first Bumper rocket is launched from Cape Canaveral, Florida. The Bumper was a two-stage rocket consisting of a Post-War V-2 topped by a WAC Corporal rocket. It could reach then-record altitudes of almost 400 km. Launched by General Electric Company, this Bumper was used primarily for testing rocket systems and for research on the upper atmosphere. They carried small payloads that allowed them to measure attributes including air temperature and cosmic ray impacts. (from Space exploration)
Apollo 16 LEM Orion, the Lunar Roving Vehicle and astronaut John Young (1972) (from Space exploration)
This is an artist's concept of the metric expansion of space, 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)
SpaceShipOne completed the first human private spaceflight in 2004, reaching an altitude of 100.12 km (62.21 mi).
Mariner 10 image of Venus (1974) (from Space exploration)
A star-forming region in the Large Magellanic Cloud, perhaps the closest Galaxy to Earth's Milky Way (from Outer space)
Asteroid 4 Vesta, imaged by the Dawn spacecraft (2011) (from Space exploration)
Three-dimensional structure in Pillars of Creation. (from Interstellar medium)
Chandra, Hubble, and Spitzer image NGC 1952 (from Space exploration)
Most orbital flight actually takes place in upper layers of the atmosphere, especially in the thermosphere (not to scale) (from Space exploration)
Bow shock formed by the magnetosphere of the young star LL Orionis (center) as it collides with the Orion Nebula flow
Tupan Patera on Io(from Space exploration)A proposed timeline of the origin of space, from physical cosmology (from Outline of space science)
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)
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)
Lunar Gateway, one of the planned space stations for crewed cislunar travel in the 2020s (from Outer space)
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)
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
A micrometeoroid left this crater on the surface of Space Shuttle Challenger's front window on STS-7. (from Space debris)
Saudi officials inspect a crashed PAM-D module in January 2001. (from Space debris)
Cosmic dust of the Andromeda Galaxy as revealed in infrared light by the Spitzer Space Telescope. (from Cosmic dust)
Astronaut Piers Sellers during the third spacewalk of STS-121, a demonstration of orbiter heat shield repair techniques (from Outline of space science)
Spent upper stage of a Delta II rocket, photographed by the XSS 10 satellite (from Space debris)
Objects in Earth orbit including fragmentation debris. November 2020 NASA:ODPO (from Space debris)
A drifting thermal blanket photographed in 1998 during STS-88. (from Space debris)
The Moon (2010) (from Space exploration)
Known orbit planes of Fengyun-1C debris one month after the weather satellite's disintegration by the Chinese ASAT (from Space debris)
The original Magdeburg hemispheres (lower left) used to demonstrate Otto von Guericke's vacuum pump (right)
A picture of Neptune taken by Voyager 2 (1989) (from Space exploration)
A computer-generated image representing the locations, but not relative sizes, of space debris as could be seen from high Earth orbit. 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)
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)
Delta-v's in km/s for various orbital maneuvers (from Space exploration)
Cosmic dust of the Horsehead Nebula as revealed by the Hubble Space Telescope. (from Cosmic dust)
The Long Duration Exposure Facility (LDEF) is an important source of information on small-particle space debris. (from Space debris)
Aurora australis observed from the Space Shuttle Discovery, on STS-39, May 1991 (orbital altitude: 260 km)
Baker-Nunn cameras were widely used to study space debris. (from Space debris)
Comet 103P/Hartley (2010) (from Space exploration)
Buzz Aldrin and Apollo 11's lunar lander on the Moon's surface (from Space exploration)
The Moon as seen in a digitally processed image from data collected during the 1992 Galileo spacecraft flyby (from Space exploration)
A picture of Saturn taken by Cassini (2004) (from Space exploration)
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.
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)
Triton as imaged by Voyager 2 (1989) (from Space exploration)
Star cluster Pismis 24 and NGC 6357 (from Space exploration)
The diversity found in the different types and scales of astronomical objects make the field of study increasingly specialized. (from Outline of space science)
Voyager 1 is the first artificial object to reach the interstellar medium. (from Interstellar medium)
First television image of Earth from space, taken by TIROS-1. (1960) (from Space exploration)
Because of the hazards of a vacuum, astronauts must wear a pressurized space suit while off-Earth and outside their spacecraft.
The United States' planned Space Launch System concept art (from Space exploration)
Orbit of 2020 SO (from Space debris)
This light-year-long knot of interstellar gas and dust resembles a caterpillar. (from Interstellar medium)
Phobos (moon) (2008) (from Space exploration)
A MESSENGER image from 18,000 km showing a region about 500 km across (2008) (from Space exploration)
Smooth chondrite interplanetary dust particle. (from Cosmic dust)
A view beneath the clouds of Titan, as seen in false colour, created from a mosaic of images taken by Cassini (2013) (from Space exploration)
Concept art for a NASA Vision mission (from Space exploration)
Apollo CSM in lunar orbit (from Space exploration)
Astronaut Buzz Aldrin had a personal Communion service when he first arrived on the surface of the Moon. (from Space exploration)
New Horizons image of Charon (2015) (from Space exploration)
Artistic image of a rocket lifting from a Saturn moon (from Space exploration)
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)
2008 launch of the SM-3 missile used to destroy American reconnaissance satellite USA-193
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)
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)
The interface between the 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)
Satellite hit by a space debris, animation by ESA (from Space debris)
The Blue Marble Earth picture taken during Apollo 17 (1972) (from Space exploration)
A dusty trail from the early Solar System to carbonaceous dust today. (from Cosmic dust)
MESSENGER image of Mercury (2013) (from Space exploration)
Vanguard 1 is expected to remain in orbit for 240 years. (from Space debris)
Sputnik 1, the first artificial satellite orbited Earth at 939 to 215 km (583 to 134 mi) in 1957, and was soon followed by Sputnik 2. See First satellite by country (Replica Pictured) (from Space exploration)
Surface of Mars by the Spirit rover (2004) (from Space exploration)
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)
Uranus as imaged by Voyager 2 (1986) (from Space exploration)
Zodiacal light caused by cosmic dust. (from Cosmic dust)
Mars, as seen by the Hubble Space Telescope (2003) (from Space exploration)
Crew quarters on Zvezda the base ISS crew module (from Space exploration)
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