Space plasmas Space plasmas An astrophysical plasma is a plasmas (an ionized gas) found in astronomy whose physical properties are studied in the science of astrophysics. Around 99% of the universe is thought to consist of plasma, a state of matter in which atoms and molecules are so hot, that they have ionized by breaking up into their constituent parts, negatively charged electrons and positively charged ions. Although influenced by gravity, because the particles are charged, they are also strongly influenced by electromagnetic forces, that is, by magnetic and electric fields. ...more on Wikipedia about "Astrophysical plasma"
The aurora is a glow observed in the night sky usually in the polar zone. It is also known as "northern lights" or "aurora borealis," Latin for "northern dawn" since (in Europe especially) it often appears as a reddish glow on the northern horizon, as if the sun were rising from an unusual direction. Aurora borealis most often occurs from September to October and March to April. Its southern counterpart "aurora australis," has similar properties, so scientists prefer "polar aurora" (or "aurora polaris"). Dr Tony Phillips ( NASA Spaceweather.com ) collects and publishs images of Auroral displays from both hemispheres. ...more on Wikipedia about "Aurora (astronomy)"
A Birkeland current generally refers to any electric current in a space plasma, but more specifically when charged particles in the current follow magnetic field lines. They are caused by the movement of a plasma perpendicular to a magnetic field. Birkeland currents often show filamentary, or twisted "rope-like" magnetic structure. They are sometimes referred to as field-aligned currents. ...more on Wikipedia about "Birkeland current"
In astronomy, a corona is the luminous plasma " atmosphere" of the Sun or other celestial body, extending millions of kilometres into space, most easily seen during a total solar eclipse, but also observable in a coronagraph. ...more on Wikipedia about "Corona"
A double layer is an electric charge separation region that forms in a plasma. It consists of two oppositely charged parallel layers, resulting in a voltage drop and electric field across the layer, which accelerates the plasma's electrons and positive ions in opposite directions, producing an electric current. All electrons spiralling through a magnetic field will produce radiation, and a large potential drop across the layer may accelerate electrons to relativistic velocities (ie close to the speed of light), which may produce synchrotron radiation. ...more on Wikipedia about "Double layer"
In astronomy, the heliopause is the boundary where the Sun's solar wind is stopped by the interstellar medium. ...more on Wikipedia about "Heliopause"
The heliosheath is the zone between the termination shock and the heliopause at the outer border of the solar system. It lies along the edge of the heliosphere, a "bubble" caused by solar winds. ...more on Wikipedia about "Heliosheath"
The heliosphere is a bubble in space produced by the solar wind. Although electrically neutral atoms from interstellar space can penetrate this bubble, virtually all of the material in the heliosphere emanates from the Sun itself. ...more on Wikipedia about "Heliosphere"
The Heliospheric current sheet (HCS) is the surface within the Solar System where the polarity of the Sun's magnetic field changes from plus (north) to minus (south). This field extends from the Sun's equatorial plane throughout the entire Solar System, and can be considered its largest structure ** . The shape of the current sheet results from the influence of the Sun's rotating magnetic field on the plasma in the interplanetary medium ( Solar Wind) ** . A small electrical current flows within the sheet, about 10-10 amps/m2. The thickness of the current sheet is about 10,000km. ...more on Wikipedia about "Heliospheric current sheet"
The High Frequency Active Auroral Research Program (HAARP) is an investigation project to "understand, simulate and control ionospheric processes that might alter the performance of communication and surveillance systems". Started in 1993, the project is proposed to last for a period of twenty years. ...more on Wikipedia about "High Frequency Active Auroral Research Program"
Intergalactic space is the physical space between galaxies. Generally free of dust and debris, intergalactic space is very close to a vacuum. The average density of the Universe is less than one atom per cubic meter. The density of the Universe, however, is clearly not uniform; it ranges from relatively high density in galaxies (including very high density in structures within galaxies, such as planets, stars, and black holes) to extremely rarified conditions in vast voids that have lower density than the Universe's average. Surrounding and stretching between galaxies, there is a rarified gas that is thought to possess a cosmic filamentary structure and that is slightly denser than the average density in the Universe. This material is called the intergalactic medium (IGM) and is mostly ionized hydrogen (i.e. a plasma) consisting of equal numbers of electrons and protons. The IGM is thought to exist at a density of 10 to 100 times the average density of the Universe -- which implies the mass of 10 to 100 hydrogen atoms per cubic meter. ...more on Wikipedia about "Intergalactic space"
The interplanetary medium is the material which fills the solar system and through which all the larger solar system bodies such as planets, asteroids and comets move. ...more on Wikipedia about "Interplanetary medium"
The ionosphere is the part of the atmosphere that is ionized by solar radiation. It forms the inner edge of the magnetosphere and has practical importance because it influences high-frequency (HF) (3–30 MHz) radio propagation to distant places on the Earth. ...more on Wikipedia about "Ionosphere"
Lightning is a powerful natural electrostatic discharge produced during a thunderstorm. Lightning's abrupt electric discharge is accompanied by the emission of visible light and other forms of electromagnetic radiation. The electric current passing through the discharge channels rapidly heats and expands the air into plasma, producing acoustic shock waves ( thunder) in the atmosphere. ...more on Wikipedia about "Lightning"
Fast http://www.shortopedia.com
Magnetohydrodynamics (MHD) (magnetofluiddynamics or hydromagnetics), is the academic discipline which studies the dynamics of electrically conducting fluids. Examples of such fluids include plasmas, liquid metals, and salt water. The word magnetohydrodynamics (MHD) is derived from magneto- meaning magnetic field, and hydro- meaning fluid, and - dynamics meaning movement. The field of MHD was initiated by Hannes Alfvén, for which he received the Nobel Prize in 1970. ...more on Wikipedia about "Magnetohydrodynamics"
A magnetopause flows along the boundary between a magnetic field, (see: magnetosphere) and surrounding plasma. It behaves roughly like a droplet of liquid exposed to supersonic flow. The magnetopause will ripple, flap, and sometimes droplets will break off. ...more on Wikipedia about "Magnetopause"
The magnetosheath refers to the region of space between the magnetopause and the bow shock of a planet's magnetosphere. The regularly organized magnetic field generated by the planet becomes weak and irregular in the magnetosheath due to interaction with the incoming solar wind, and is incapable of fully deflecting the highly charged particles. The density of the particles in this region is considerably lower than what is found beyond the bow shock, but greater than within the magnetopause, and can be considered a transitory state. ...more on Wikipedia about "Magnetosheath"
(Magnetosphere) (Please see "Note to Users" at end!) ...more on Wikipedia about "Magnetosphere"
A nebula ( Latin: "mist"; pl. nebulae) is an interstellar cloud of dust, gas and plasma. Originally nebula was a general name for any extended astronomical object, including galaxies beyond the Milky Way (some examples of the older usage survive; for example, the Andromeda Galaxy is sometimes referred to as the Andromeda Nebula). ...more on Wikipedia about "Nebula"
A planetary nebula is an astronomical object consisting of a glowing shell of gas and plasma formed by certain types of stars at the end of their lives. They are in fact unrelated to planets; the name originates from a supposed similarity in appearance to giant planets. They are a short-lived phenomenon, lasting a few tens of thousands of years, compared to a typical stellar lifetime of several billion years. About 1,500 are known to exist in our galaxy. ...more on Wikipedia about "Planetary nebula"
Plasma cosmology is a cosmological model based on the electromagnetic properties of astrophysical plasmas. Plasma cosmology explains the large scale structure and evolution of the universe, from galaxy formation to the cosmic microwave background by invoking electromagnetic phenomena associated with laboratory plasmas. ...more on Wikipedia about "Plasma cosmology" www.shortopedia.com, it's as simple as that! Space_plasmas
This scaling applies best to plasmas with a relatively low degree of ionization. In such plasmas, the ionization energy of the neutral atoms is an important parameter and establishes an absolute energy scale, which explains many of the scalings in the table: ...more on Wikipedia about "Plasma scaling"
A plasmoid is a coherent structure of plasma and magnetic fields. Plasmoids have been proposed to explain natural phenomena such as ball lightning , magnetic bubbles in the magnetosphere , and objects in cometary tails , in the solar wind , in the solar atmoshphere , and in the heliospheric current sheet . Plasmoids produced in the laboratory include Field-Reversed Configurations, Stellarators, and the dense plasma focus. ...more on Wikipedia about "Plasmoid"
In Big Bang cosmology, Reionization is the process that reionized the matter in the universe after the epoch of galaxy formation. It is the second of two major phase changes of hydrogen gas in the universe. The first is recombination, happening at a redshift (400,000 years after the big bang), at which time the cooling due to the expansion of the universe brought it to a temperature such that the hydrogen recombination rate was greater than the ionization rate (the ionization rate increases with increasing temperature), allowing protons to recombine with an equivalent number of electrons. The second phase change, reionization, is thought to have occurred when the first few generations of population III stars and quasars emitted radiation that reionized the universe, making it once again an ionized plasma (