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List Of Space Observatories
This list of space telescopes (astronomical space observatories) is grouped by major frequency ranges: gamma ray, x-ray, ultraviolet, visible, infrared, microwave and radio. Telescopes that work in multiple frequency bands are included in all of the appropriate sections. Space telescopes that collect particles, such as cosmic ray nuclei and/or electrons, as well as instruments that aim to detect gravitational waves, are also listed. Missions with specific targets within the Solar System (e.g. the Sun and its planets), are excluded; see List of Solar System probes for these, and List of Earth observation satellites for missions targeting Earth. Two values are provided for the dimensions of the initial orbit. For telescopes in Earth orbit, the min and max altitude are given in kilometers. For telescopes in solar orbit, the minimum distance (periapsis) and the maximum distance (apoapsis) between the telescope and the center of mass of the sun are given in astronomical units ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hubble 01
The Hubble Space Telescope (often referred to as HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most versatile, renowned both as a vital research tool and as a public relations boon for astronomy. The Hubble telescope is named after astronomer Edwin Hubble and is one of NASA's Great Observatories. The Space Telescope Science Institute (STScI) selects Hubble's targets and processes the resulting data, while the Goddard Space Flight Center (GSFC) controls the spacecraft. Hubble features a mirror, and its five main instruments observe in the ultraviolet, visible spectrum, visible, and near-infrared regions of the electromagnetic spectrum. Hubble's orbit outside the distortion of atmosphere of Earth, Earth's atmosphere allows it to capture extremely high-resolution images with substantially lower background light than ground-based telescopes. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Solar System Probes
This is a list of space probes that have left Earth orbit (or were launched with that intention but failed), organized by their planned destination. It includes planetary probes, solar probes, and probes to asteroids and comets, but excludes lunar missions, which are listed separately at List of lunar probes and List of Apollo missions. Flybys (such as gravity assists) that were incidental to the main purpose of the mission are also included. Flybys of Earth are listed separately at List of Earth flybys. Confirmed future probes are included, but missions that are still at the concept stage, or which never progressed beyond the concept stage, are not. Key Colour key: * † means "tentatively identified", as classified by NASA. These are Cold War-era Soviet missions, mostly failures, about which few or no details have been officially released. The information given may be speculative. * Date is the date of: :* closest encounter (flybys) :* impact (impactors) :* orbital inser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutron Star
A neutron star is the collapsed core of a massive supergiant star, which had a total mass of between 10 and 25 solar masses, possibly more if the star was especially metal-rich. Except for black holes and some hypothetical objects (e.g. white holes, quark stars, and strange stars), neutron stars are the smallest and densest currently known class of stellar objects. Neutron stars have a radius on the order of and a mass of about 1.4 solar masses. They result from the supernova explosion of a massive star, combined with gravitational collapse, that compresses the core past white dwarf star density to that of atomic nuclei. Once formed, they no longer actively generate heat, and cool over time; however, they may still evolve further through collision or accretion. Most of the basic models for these objects imply that neutron stars are composed almost entirely of neutrons (subatomic particles with no net electrical charge and with slightly larger mass than protons); th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supernova
A supernova is a powerful and luminous explosion of a star. It has the plural form supernovae or supernovas, and is abbreviated SN or SNe. This transient astronomical event occurs during the last evolutionary stages of a massive star or when a white dwarf is triggered into runaway nuclear fusion. The original object, called the ''progenitor'', either collapses to a neutron star or black hole, or is completely destroyed. The peak optical luminosity of a supernova can be comparable to that of an entire galaxy before fading over several weeks or months. Supernovae are more energetic than novae. In Latin, ''nova'' means "new", referring astronomically to what appears to be a temporary new bright star. Adding the prefix "super-" distinguishes supernovae from ordinary novae, which are far less luminous. The word ''supernova'' was coined by Walter Baade and Fritz Zwicky in 1929. The last supernova to be directly observed in the Milky Way was Kepler's Supernova in 1604, ap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-altitude Balloon
High-altitude balloons are crewed or uncrewed balloons, usually filled with helium or hydrogen, that are released into the stratosphere, generally attaining between above sea level. In 2002, a balloon named BU60-1 reached a record altitude of . The most common type of high-altitude balloons is weather balloons. Other purposes include use as a platform for experiments in the upper atmosphere. Modern balloons generally contain electronic equipment such as radio transmitters, cameras, or satellite navigation systems, such as GPS receivers. These balloons are launched into what is termed "near space", defined as the area of Earth's atmosphere between the Armstrong limit ( above sea level), where pressure falls to the point that a human being cannot survive without a pressurised suit, and the Kármán line ( above sea level), where astrodynamics must take over from aerodynamics in order to maintain flight. Due to the low cost of GPS and communications equipment, high-altitude ballo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomical Unit
The astronomical unit (symbol: au, or or AU) is a unit of length, roughly the distance from Earth to the Sun and approximately equal to or 8.3 light-minutes. The actual distance from Earth to the Sun varies by about 3% as Earth orbits the Sun, from a maximum (aphelion) to a minimum (perihelion) and back again once each year. The astronomical unit was originally conceived as the average of Earth's aphelion and perihelion; however, since 2012 it has been defined as exactly (see below for several conversions). The astronomical unit is used primarily for measuring distances within the Solar System or around other stars. It is also a fundamental component in the definition of another unit of astronomical length, the parsec. History of symbol usage A variety of unit symbols and abbreviations have been in use for the astronomical unit. In a 1976 resolution, the International Astronomical Union (IAU) had used the symbol ''A'' to denote a length equal to the astronomic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Center Of Mass
In physics, the center of mass of a distribution of mass in space (sometimes referred to as the balance point) is the unique point where the weighted relative position of the distributed mass sums to zero. This is the point to which a force may be applied to cause a linear acceleration without an angular acceleration. Calculations in mechanics are often simplified when formulated with respect to the center of mass. It is a hypothetical point where the entire mass of an object may be assumed to be concentrated to visualise its motion. In other words, the center of mass is the particle equivalent of a given object for application of Newton's laws of motion. In the case of a single rigid body, the center of mass is fixed in relation to the body, and if the body has uniform density, it will be located at the centroid. The center of mass may be located outside the physical body, as is sometimes the case for hollow or open-shaped objects, such as a horseshoe. In the case of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apoapsis
An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any elliptic orbit. The name for each apsis is created from the prefixes ''ap-'', ''apo-'' (), or ''peri-'' (), each referring to the farthest and closest point to the primary body the affixing necessary suffix that describes the primary body in the orbit. In this case, the suffix for Earth is ''-gee'', so the apsides' names are ''apogee'' and ''perigee''. For the Sun, its suffix is ''-helion'', so the names are ''aphelion'' and ''perihelion''. According to Newton's laws of motion, all periodic orbits are ellipses. The barycenter of the two bodies may lie well within the bigger body—e.g., the Earth–Moon barycenter is about 75% of the way from Earth's center to its surface. If, compared to the larger mass, the smaller mass is negligible (e.g., ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Periapsis
An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any elliptic orbit. The name for each apsis is created from the prefixes ''ap-'', ''apo-'' (), or ''peri-'' (), each referring to the farthest and closest point to the primary body the affixing necessary suffix that describes the primary body in the orbit. In this case, the suffix for Earth is ''-gee'', so the apsides' names are ''apogee'' and ''perigee''. For the Sun, its suffix is ''-helion'', so the names are ''aphelion'' and ''perihelion''. According to Newton's laws of motion, all periodic orbits are ellipses. The barycenter of the two bodies may lie well within the bigger body—e.g., the Earth–Moon barycenter is about 75% of the way from Earth's center to its surface. If, compared to the larger mass, the smaller mass is negligible (e.g., ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Orbit
A heliocentric orbit (also called circumsolar orbit) is an orbit around the barycenter of the Solar System, which is usually located within or very near the surface of the Sun. All planets, comets, and asteroids in the Solar System, and the Sun itself are in such orbits, as are many artificial probes and pieces of debris. The moons of planets in the Solar System, by contrast, are not in heliocentric orbits, as they orbit their respective planet (although the Moon has a convex orbit around the Sun). The barycenter of the Solar System, while always very near the Sun, moves through space as time passes, depending on where other large bodies in the Solar System, such as Jupiter and other large gas planets, are located at that time. A similar phenomenon allows the detection of exoplanets by way of the radial-velocity method. The ''helio-'' prefix is derived from the Greek word "ἥλιος", meaning "Sun", and also Helios, the personification of the Sun in Greek mythology. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kilometer
The kilometre ( SI symbol: km; or ), spelt kilometer in American English, is a unit of length in the International System of Units (SI), equal to one thousand metres (kilo- being the SI prefix for ). It is now the measurement unit used for expressing distances between geographical places on land in most of the world; notable exceptions are the United States and the United Kingdom where the statute mile is the unit used. The abbreviations k or K (pronounced ) are commonly used to represent kilometre, but are not recommended by the BIPM. A slang term for the kilometre in the US, UK, and Canadian militaries is ''klick''. Pronunciation There are two common pronunciations for the word. # # The first pronunciation follows a pattern in English whereby metric units are pronounced with the stress on the first syllable (as in kilogram, kilojoule and kilohertz) and the pronunciation of the actual base unit does not change irrespective of the prefix (as in centimetre, millimetre, n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Altitude
Altitude or height (also sometimes known as depth) is a distance measurement, usually in the vertical or "up" direction, between a reference datum and a point or object. The exact definition and reference datum varies according to the context (e.g., aviation, geometry, geographical survey, sport, or atmospheric pressure). Although the term ''altitude'' is commonly used to mean the height above sea level of a location, in geography the term elevation is often preferred for this usage. Vertical distance measurements in the "down" direction are commonly referred to as depth. In aviation In aviation, the term altitude can have several meanings, and is always qualified by explicitly adding a modifier (e.g. "true altitude"), or implicitly through the context of the communication. Parties exchanging altitude information must be clear which definition is being used. Aviation altitude is measured using either mean sea level (MSL) or local ground level (above ground level, or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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