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Solar Wind Turbulence
Solar wind turbulence refers to the complex, chaotic fluid motions and magnetic field fluctuations observed in the solar wind plasma as it flows outward from the Sun. This turbulence plays a key role in heating the solar wind and accelerating charged particles throughout the heliosphere. Solar wind turbulence displays both magnetohydrodynamic (MHD) and kinetic plasma behaviors. It exhibits Kolmogorov-like power spectra at fluid scales, and shows strong Alfvénic correlations between velocity and magnetic field fluctuations, especially in fast solar wind. It evolves with distance from the Sun as the wind expands. The turbulence can be broadly categorized into: *Large-scale Alfvénic fluctuations originating from the Sun *Actively evolving turbulent cascade transferring energy to smaller scales *Small-scale kinetic processes where the fluid approximation breaks down Observations from spacecraft like Helios, Ulysses, and Wind Wind is the natural movement of atmosphere of Eart ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turbulence
In fluid dynamics, turbulence or turbulent flow is fluid motion characterized by chaotic changes in pressure and flow velocity. It is in contrast to laminar flow, which occurs when a fluid flows in parallel layers with no disruption between those layers. Turbulence is commonly observed in everyday phenomena such as surf, fast flowing rivers, billowing storm clouds, or smoke from a chimney, and most fluid flows occurring in nature or created in engineering applications are turbulent. Turbulence is caused by excessive kinetic energy in parts of a fluid flow, which overcomes the damping effect of the fluid's viscosity. For this reason, turbulence is commonly realized in low viscosity fluids. In general terms, in turbulent flow, unsteady vortices appear of many sizes which interact with each other, consequently drag due to friction effects increases. The onset of turbulence can be predicted by the dimensionless Reynolds number, the ratio of kinetic energy to viscous damping ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Wind
The solar wind is a stream of charged particles released from the Sun's outermost atmospheric layer, the Stellar corona, corona. This Plasma (physics), plasma mostly consists of electrons, protons and alpha particles with kinetic energy between . The composition of the solar wind plasma also includes a mixture of particle species found in the solar plasma: trace amounts of heavy ions and atomic nuclei of Chemical element, elements such as carbon, nitrogen, oxygen, neon, magnesium, silicon, sulfur, and iron. There are also rarer traces of some other nuclei and isotopes such as phosphorus, titanium, chromium, and nickel's isotopes 58Ni, 60Ni, and 62Ni. Superimposed with the solar-wind plasma is the interplanetary magnetic field. The solar wind varies in density, temperature and speed over time and over Solar coordinate systems#Heliographic, solar latitude and longitude. Its particles can escape the Sun's gravity because of their high energy resulting from the high temperature of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasma (physics)
Plasma () is a state of matter characterized by the presence of a significant portion of charged particles in any combination of ions or electrons. It is the most abundant form of ordinary matter in the universe, mostly in stars (including the Sun), but also dominating the rarefied intracluster medium and Outer space#Intergalactic space, intergalactic medium. Plasma can be artificially generated, for example, by heating a neutral gas or subjecting it to a strong electromagnetic field. The presence of charged particles makes plasma electrically conductive, with the dynamics of individual particles and macroscopic plasma motion governed by collective electromagnetic fields and very sensitive to externally applied fields. The response of plasma to electromagnetic fields is used in many modern devices and technologies, such as plasma display, plasma televisions or plasma etching. Depending on temperature and density, a certain number of neutral particles may also be present, in wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helios (spacecraft)
''Helios-A'' and ''Helios-B'' (after launch renamed ' and ') are a pair of probes that were launched into heliocentric orbit to study solar processes. As a joint venture between German Aerospace Center (DLR) and NASA, the probes were launched from Cape Canaveral Air Force Station, Florida, on December10, 1974, and January15, 1976, respectively. The Helios project set a maximum speed record for spacecraft of . ''Helios-B'' performed the closest flyby of the Sun of any spacecraft until that time. The probes are no longer functional, but as of 2024 remain in elliptical orbits around the Sun. Construction The Helios project was a joint venture of West Germany's space agency DLR (70 percent share) and NASA (30 percent share). As built by the main contractor, Messerschmitt-Bölkow-Blohm, they were the first space probes built outside the United States and the Soviet Union to leave Earth orbit. Structure The two ''Helios'' probes look similar. ''Helios-A'' has a mass of , an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ulysses (spacecraft)
''Ulysses'' ( , ) was a Uncrewed spacecraft, robotic space probe whose primary mission was to orbit the Sun and study it at all latitudes. It was launched in 1990 and made three "fast latitude scans" of the Sun in 1994/1995, 2000/2001, and 2007/2008. In addition, the probe studied several comets. ''Ulysses'' was a joint venture of the European Space Agency (ESA) and the United States' NASA, National Aeronautics and Space Administration (NASA), under leadership of ESA with participation from Canada's National Research Council (Canada), National Research Council. The last day for mission operations on ''Ulysses'' was 30 June 2009. To study the Sun at all latitudes, the probe needed to change its orbital inclination and leave the Ecliptic, plane of the Solar System. To change the orbital inclination of a spacecraft to about 80° requires a large change in heliocentric velocity, the energy to achieve which far exceeded the capabilities of any launch vehicle. To reach the desired ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasma Phenomena
Plasma or plasm may refer to: Science * Plasma (physics), one of the four fundamental states of matter * Plasma (mineral), a green translucent silica mineral * Quark–gluon plasma, a state of matter in quantum chromodynamics Biology * Blood plasma, the yellow-colored liquid component of blood, in which blood cells are suspended * Cytoplasm, a jelly-like substance that fills cells, suspends and protects organelles * Germ plasm, a zone in the cytoplasm determining germ cells * Germplasm, a collection of genetic resources for an organism * Milk plasma or whey, the liquid remaining after milk has been curdled and strained * Nucleoplasm, a highly viscous liquid that surrounds the chromosomes and nucleoli * Plasma cell, white blood cells that secrete large volumes of antibodies * Protoplasm, the entire living substance inside the cell membrane or cell wall Technology * Plasma (game engine), a real-time 3D game engine from Cyan Worlds * Plasma display, a flat-panel electronic visual d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
