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.

Illustration of Earth's atmosphere gradual transition into outer space

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.

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

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.

Selected picture

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  Planet Mars

  Mars (planet)

  Credit: NASA

  Mars, 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.
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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.
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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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  Astronaut Bruce McCandless using a Manned Maneuvering Unit

  Manned Maneuvering Unit

  Credit: NASA

  A 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.

  
  
  
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  Pale Blue Dot

  Photo credit: NASA/JPL

  Pale 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."
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  Neptune

  Photograph credit: NASA / JPL

  Neptune is the eighth and farthest known planet from the Sun in the Solar System. In the Solar System, it is the fourth-largest planet by diameter, the third-most-massive planet and the densest giant planet. Neptune is 17 times the mass of Earth, slightly more massive than its near-twin Uranus. Neptune is denser and physically smaller than Uranus because its greater mass causes more gravitational compression of its atmosphere. Neptune orbits the Sun once every 164.8 years at an average distance of 30.1 au (4.5 billion km; 2.8 billion mi). It is named after the Roman god of the sea and has the astronomical symbol ♆, a stylised version of the god Neptune's trident.
  
  This picture of Neptune was taken by NASA's Voyager 2 spacecraft in 1989, at a range of 4.4 million miles (7.1 million kilometres) from the planet, approximately four days before closest approach. The photograph shows the Great Dark Spot, a storm about the size of Earth, in the centre, while the fast-moving bright feature nicknamed the "Scooter" and the Small Dark Spot can be seen on the western limb. These clouds were seen to persist for as long as the spacecraft's cameras could resolve them.
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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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  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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  Olympus Mons

  Image credit: United States Geological Survey

  A 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.
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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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  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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  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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  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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  NGC 6357

  Photograph credit: NASA

  NGC 6357 is a diffuse nebula in the constellation Scorpius. This composite image of the nebula contains X-ray data from the Chandra X-ray Observatory and the ROSAT telescope (purple), infrared data from the Spitzer Space Telescope (orange), and optical data from the SuperCosmos Sky Survey (blue). Radiation from hot, young stars is energizing the cooler gas in the clouds that surround them. Often known as the Lobster Nebula, the astronomical object has also been termed the Madokami Nebula by fans of the anime Madoka Magica due to its supposed resemblance to the main character. Scientists at the Midcourse Space Experiment prefer the name War and Peace Nebula, because the bright, western part resembles a dove, while the eastern part looks like a skull in infrared images.
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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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  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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  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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  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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  Eagle Nebula

  Photo credit: NASA

  The Eagle Nebula (also known as Messier Object 16, M16 or NGC 6611) is a young open cluster of stars. The nebula is an active region of star formation. Light from the bright, hot, young stars near the centre of the cluster illuminate the clouds of hydrogen gas and dust still collapsing to form new stars.
  
  As projected on the sky, the Eagle Nebula lies in the constellation of Serpens Cauda. In three dimensions, it is relatively close to the Solar System being some 7,000 light years away on the edge of the Sagittarius Arm, the next nearest spiral arm towards the centre of the Milky Way.
  
  In fact, when the picture is not coloured, is only red colored, the "Eagle" can be seen as a dark spot in the center of the nebula.
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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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  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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  Earthrise, as seen by Apollo 8

  Apollo 8

  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.

  
  
  

Space-related portals

General images

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

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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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  Near-Earth space (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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  The Long Duration Exposure Facility (LDEF) is an important source of information on small-particle space debris. (from Space debris)
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  Earth and the Moon as seen from space on the 2022 Artemis 1 mission (from Outer space)
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  Self-portrait of Curiosity rover on Mars's surface (from Space exploration)
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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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  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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  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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  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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  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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  Comet 103P/Hartley (2010) (from Space exploration)
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  Model of Vostok spacecraft (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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  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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  Saudi officials inspect a crashed PAM-D module in January 2001. (from Space debris)
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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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  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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  Tupan Patera on Io (from Space exploration)
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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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  Crew quarters on Zvezda, the base ISS crew module (from Space exploration)
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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 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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  A computer-generated map of objects orbiting Earth. About 95% are debris, not working artificial satellites (from Outer space)
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  Porous chondrite dust particle (from Cosmic dust)
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  Asteroid 4 Vesta, imaged by the Dawn spacecraft (2011) (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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  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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  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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  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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  Baker-Nunn cameras were widely used to study space debris. (from Space debris)
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  This light-year-long knot of interstellar gas and dust resembles a caterpillar. (from Interstellar medium)
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  Apollo CSM in lunar orbit (from Space exploration)
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  A drifting thermal blanket photographed in 1998 during STS-88. (from Space debris)
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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 space law, even though they create hazardous space debris (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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  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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  Illustration of Earth's atmosphere gradual transition into outer space (from Outer space)
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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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  Herbig–Haro object HH 110 ejects gas through interstellar space. (from Interstellar medium)
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  V-2 Rocket in the Peenemünde Museum (from Space exploration)
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  Major elements of 200 stratospheric interplanetary dust particles. (from Cosmic dust)
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  Three-dimensional structure in Pillars of Creation. (from Interstellar medium)
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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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  Vanguard 1 is expected to remain in orbit for 240 years. (from Space debris)
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  Concept art for a NASA Vision mission (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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  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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  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 micrometeoroid left this crater on the surface of Space Shuttle Challenger's front window on STS-7. (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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  The original Magdeburg hemispheres (left) used to demonstrate Otto von Guericke's vacuum pump (right)
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  A dusty trail from the early Solar System to carbonaceous dust today. (from Cosmic dust)
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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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  Delta-v's in km/s for various orbital maneuvers (from Space exploration)
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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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  Objects in Earth orbit including fragmentation debris. November 2020 NASA:ODPO (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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  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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  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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  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 proposed timeline of the origin of space, from physical cosmology (from Outline of space science)
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  Perseverance's backshell sitting upright on the surface of Jezero Crater (from Space debris)
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  Zodiacal light caused by cosmic dust. (from Cosmic dust)
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  Interstellar medium and astrosphere meeting (from Interstellar medium)
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  Artist's impression of dust formation around a supernova explosion. (from Cosmic dust)
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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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  Debris density in low Earth orbit (from Space debris)
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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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  Artistic image of a rocket lifting from a Saturn moon (from Space exploration)

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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