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Planck (spacecraft)
''Planck'' was a space observatory operated by the European Space Agency (ESA) from 2009 to 2013, which mapped the anisotropies of the cosmic microwave background (CMB) at microwave and infrared frequencies, with high sensitivity and small angular resolution. The mission substantially improved upon observations made by the NASA Wilkinson Microwave Anisotropy Probe (WMAP). ''Planck'' provided a major source of information relevant to several cosmological and astrophysical issues, such as testing theories of the early Universe and the origin of cosmic structure. Since the end of its mission, ''Planck'' has defined the most precise measurements of several key cosmological parameters, including the average density of ordinary matter and dark matter in the Universe and the age of the universe. The project was started around 1996 and was initially called COBRAS/SAMBA: the Cosmic Background Radiation Anisotropy Satellite/Satellite for Measurement of Background Anisotropies. It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
European Space Agency
, owners = , headquarters = Paris, Île-de-France, France , coordinates = , spaceport = Guiana Space Centre , seal = File:ESA emblem seal.png , seal_size = 130px , image = Views in the Main Control Room (12052189474).jpg , size = , caption = , acronym = , established = , employees = 2,200 , administrator = Director General Josef Aschbacher , budget = €7.2 billion (2022) , language = English and French (working languages) , website = , logo = European Space Agency logo.svg , logo_caption = Logo , image_caption = European Space Operations Centre (ESOC) Main Control Room The European Space Agency (ESA; french: Agence spatiale européenne , it, Agenzia Spaziale Europea, es, Agencia Espacial Europea ASE; german: Europäische Weltraumorganisation) is an intergovernmental organisation of 22 member states dedicated to the exploration of space. Established in 1975 and headquartere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Matter
In classical physics and general chemistry, matter is any substance that has mass and takes up space by having volume. All everyday objects that can be touched are ultimately composed of atoms, which are made up of interacting subatomic particles, and in everyday as well as scientific usage, "matter" generally includes atoms and anything made up of them, and any particles (or combination of particles) that act as if they have both rest mass and volume. However it does not include massless particles such as photons, or other energy phenomena or waves such as light or heat. Matter exists in various states (also known as phases). These include classical everyday phases such as solid, liquid, and gas – for example water exists as ice, liquid water, and gaseous steam – but other states are possible, including plasma, Bose–Einstein condensates, fermionic condensates, and quark–gluon plasma. Usually atoms can be imagined as a nucleus of protons and neutrons, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Passivation (spacecraft)
The passivation of a spacecraft is the removal of any internal energy contained in the vehicle at the end of its mission or useful life. Spent upper stages are generally passivated after their use as launch vehicles is complete, as are satellites when they can no longer be used for their design purpose. Internally stored energy generally takes the form of unused propellant and batteries. In the past, such stored energy has sometimes led to fragmentation or explosion, producing unwanted space debris. This was a fairly common outcome for many of the U.S. and Soviet rocket designs of the 1960s to the 1980s.A. Rossi et al"Effects of the RORSAT NaK Drops on the Long Term Evolution of the Space Debris Population" University of Pisa, 1997. It remains an occasional problem with derelict second stages left in higher Earth orbits; several U.S. rocket stages fragmented in 2018 and 2019. The International Telecommunication Union (ITU) and United Nations (UN) recommend that satellites in ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graveyard Orbit
A graveyard orbit, also called a junk orbit or disposal orbit, is an orbit that lies away from common operational orbits. One significant graveyard orbit is a supersynchronous orbit well beyond geosynchronous orbit. Some satellites are moved into such orbits at the end of their operational life to reduce the probability of colliding with operational spacecraft and generating space debris. Overview A graveyard orbit is used when the change in velocity required to perform a de-orbit maneuver is too large. De-orbiting a geostationary satellite requires a delta-v of about , whereas re-orbiting it to a graveyard orbit only requires about . For satellites in geostationary orbit and geosynchronous orbits, the graveyard orbit is a few hundred kilometers beyond the operational orbit. The transfer to a graveyard orbit beyond geostationary orbit requires the same amount of fuel as a satellite needs for about three months of stationkeeping. It also requires a reliable attitude control du ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heliocentric 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. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polarization In Astronomy
Polarization is an important phenomenon in astronomy. Stars The polarization of starlight was first observed by the astronomers William Hiltner and John S. Hall in 1949. Subsequently, Jesse Greenstein and Leverett Davis, Jr. developed theories allowing the use of polarization data to trace interstellar magnetic fields. Though the integrated thermal radiation of stars is not usually appreciably polarized at source, scattering by interstellar dust can impose polarization on starlight over long distances. Net polarization at the source can occur if the photosphere itself is asymmetric, due to limb polarization. Plane polarization of starlight generated at the star itself is observed for Ap stars (peculiar A type stars Sun Both circular polarization, circular and linear polarization of sunlight has been measured. Circular polarization is mainly due to transmission and absorption effects in strongly magnetic regions of the Sun's surface. Another mechanism that gives rise to ci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Science (TV Network)
Science Channel (often simply branded as Science; abbreviated to SCI) is an American pay television channel owned by Warner Bros. Discovery. The channel features programming focusing on science related to wilderness survival, engineering, manufacturing, technology, space, space exploration, ufology and prehistory. As of February 2015, Science is available to approximately 75.5 million pay television households (64.8% of households with at least one television set) in the United States. History In November 1994, Discovery Networks announced plans for four digital channels set to launch in 1996. Discovery originally named the network under the working title Quark!; this was changed before its launch to the Discovery Science Network. Discovery Science launched in October 1996 as part of the simultaneous rollout of the new channel suite (alongside Discovery Home & Leisure, Discovery Kids and Discovery Civilization). In 2007, adult shows began airing around the clock weekdays, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
How The Universe Works
''How the Universe Works'' is a documentary science television series that originally aired on the Discovery Channel in 2010. All but the second and eighth seasons were narrated by Mike Rowe. The second and eighth seasons, as well as episodes of the fifth and sixth seasons, were narrated by Erik Todd Dellums. The first season, broadcast from April 25 to May 24, 2010, was released on Blu-ray on February 28, 2012. Since its second season, consisting of eight episodes broadcast between July 11 and August 29, 2012, the show has aired on the Science Channel. The third season aired between July 9 and September 3, 2014. The fourth season premiered on July 14, 2015, as part of the Science Channel's "Space Week," in honor of '' New Horizons''' flyby of Pluto that day; the season ran through September 1, 2015. The show's fifth season aired from November 22, 2016, through February 7, 2017. The sixth season premiered on January 9, 2018 and ran through March 13, 2018. The seventh season premi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Projects Of The European Space Agency
The European Space Agency (ESA) operates a number of missions, both operational and scientific, including collaborations with other national space agencies such as the Japan Aerospace Exploration Agency (JAXA), the National Centre for Space Studies (CNES), the Italian Space Agency (ASI), the German Aerospace Center (DLR), the National Aeronautics and Space Administration (NASA), and the China National Space Administration (CNSA). Their portfolio of missions also include many public-private partnership missions, a number of which with European satellite operators EUMETSAT, Eutelsat, and Inmarsat. A staple of the ESA's Science Doctrine is the Cosmic Vision programme, a series of space science missions chosen by the ESA to launch through competitions, similar to NASA's Discovery and New Frontiers programmes. It succeeds the Horizon 2000 and Horizon 2000+ programmes which launched notable missions such as '' Huygens'', ''Rosetta'' and ''Gaia''. Each space science mission ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cannes Mandelieu Space Center
The Cannes Mandelieu Space Center is an industrial plant dedicated to spacecraft manufacturing, located in both the towns of Cannes and Mandelieu in France. After a long history in aircraft manufacturing, starting in 1929, the center became increasingly involved in aerospace activities after the Second World War, and satellites are now the plant's main product. After having been the Satellite Division of Aérospatiale, then Alcatel Space in 1998, then Alcatel Alenia Space in 2005, the center is now part, since April 10, 2007, of Thales Alenia Space and the headquarters of the company. Main products As prime contractor * the series of Meteosat first and second generation * the series of communication satellites Spacebus * the series of Globalstar's second-generation satellites * the series of O3b satellites * the Infrared Space Observatory * the Huygens space probe, which landed on Titan * the Proteus series of small low earth orbit satellites, including ** the COROT sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black-body Radiation
Black-body radiation is the thermal electromagnetic radiation within, or surrounding, a body in thermodynamic equilibrium with its environment, emitted by a black body (an idealized opaque, non-reflective body). It has a specific, continuous spectrum of wavelengths, inversely related to intensity, that depend only on the body's temperature, which is assumed, for the sake of calculations and theory, to be uniform and constant., Chapter 13. A perfectly insulated enclosure which is in thermal equilibrium internally contains black-body radiation, and will emit it through a hole made in its wall, provided the hole is small enough to have a negligible effect upon the equilibrium. The thermal radiation spontaneously emitted by many ordinary objects can be approximated as black-body radiation. Of particular importance, although planets and stars (including the Earth and Sun) are neither in thermal equilibrium with their surroundings nor perfect black bodies, black-body radiation is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Mechanics
Quantum mechanics is a fundamental theory in physics that provides a description of the physical properties of nature at the scale of atoms and subatomic particles. It is the foundation of all quantum physics including quantum chemistry, quantum field theory, quantum technology, and quantum information science. Classical physics, the collection of theories that existed before the advent of quantum mechanics, describes many aspects of nature at an ordinary ( macroscopic) scale, but is not sufficient for describing them at small (atomic and subatomic) scales. Most theories in classical physics can be derived from quantum mechanics as an approximation valid at large (macroscopic) scale. Quantum mechanics differs from classical physics in that energy, momentum, angular momentum, and other quantities of a bound system are restricted to discrete values ( quantization); objects have characteristics of both particles and waves ( wave–particle duality); and there are lim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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