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Bow Shock The region downstream of the bow shock, between the shock and the magnetopause, that is occupied by the shocked solar wind That is, the bow shock occurs in a medium--the solar wind--that is so tenuous that collisions among the charged particles that make up the solar wind plasma are exceedingly rare and have no significant influence on the formation of the shock and the dissipation of the solar wind's kinetic energy that occurs there. Shocks are classified as "quasi-perpendicular" and "quasi-parallel" according to whether the angle (theta) between the interplanetary magnetic field (IMF) upstream of the shock and the shock normal is greater or less than 45 degrees. pluto.space.swri.edu /IMAGE/glossary/bow_shock.html   (532 words)

Space Plasma Group, QMW: Bow Shock The bow shock is the nonlinear wave which stands in the solar wind flow upstream of the Earth's magnetosphere, at which the solar wind plasma is heated and decelerated in preparation for diversion around the magnetosphere. At the bow shock the magnetic field, density and temperature all increase as the solar wind transits the shock. Observations of the bow shock show that it is a rich source of waves and energetic particles, and in situ observations have provided something like a plasma laboratory, so that much of the physics of collisionless shocks has been deciphered. www.space-plasma.qmw.ac.uk /SPGweb/SPGbowshock.html   (907 words)

Bow shock - Wikipedia, the free encyclopedia The "bow shock" shown is the bow shock caused by the sun as it moves through the interstellar medium; the Earth is too small to be seen on this scale. In a planetary magnetosphere, the bow shock is the boundary at which the solar wind abruptly drops as a result of its approach to the magnetopause. Bow shocks are also a common feature in Herbig Haro objects, in which a much stronger collimated outflow of gas and dust from the star interacts with the stellar medium, producing bright bow shocks that are visible at optical wavelengths. en.wikipedia.org /wiki/Bow_shock   (548 words)

New Model of the Earth's Bow Shock The location of the shock encounters re identified from jumps in the total magnetic field and shading shows when the spacecraft was in the magnetosheath. The shock normal was calculated using the model of the shock on December 5, 1992 obtained using the KK94 method. The shock crossings are identified using the total magnetic field and density and shading shows when the spacecraft was in the magnetosheath. www.igpp.ucla.edu /galileo/newmodel.htm   (675 words)

NASA - Voyager Enters Solar System's Final Frontier The bow shock in front of the moving heliosphere is similar to the one observed by the Hubble Space Telescope. The termination shock is where the solar wind, a thin stream of electrically charged gas blowing continuously outward from the Sun, is slowed by pressure from gas between the stars. The strongest evidence that Voyager 1 has passed through the termination shock into the slower, denser wind beyond is its measurement of an increase in the strength of the magnetic field carried by the solar wind and the inferred decrease in its speed. www.nasa.gov /vision/universe/solarsystem/voyager_agu.html   (891 words)

IRS-8 - A unique bow shock in the Galactic Center region The dust in the bow shock is heated and radiates because it is compressed by the shock and because it absorbs ultraviolet radiation from hot stars nearby, possibly including IRS-8's central star itself. The bow shock is created at the interface where the force due to the kinematic push (ram pressure) of the moving (supersonic) stellar wind bubble equalizes the thermal pressure of the local interstellar gas into which the star is moving at high speed. The second reason for the bow shock's tightness is the high velocity of the star. www.gemini.edu /science/bowshock.html   (854 words)

Aerodynamics, Acoustics, Shock Waves Propagation Shock waves are equivalent to acoustic waves in the limit of vanishing strength. Of particular interest are the impulse of a shock wave on the ground (sonic boom) and the energy radiated by a detonation. Shock waves created by supersonic bodies with a blunt nose travel ahead of the body and have a characteristic shape resembling a hyperboloid of revolution (bow shock). aerodyn.org /HighSpeed/waves.html   (865 words)

The Bow Shock is common on the distant flanks of the bow shock where the normal component of the solar wind flow is small relative to its value at the subsolar point. The model is consistent with the PVO observations of the response of the shock cross section in the terminator plane to the IMF orientation [ Zhang et al., 1991]. to the magnetic field and correspondingly the bow shock stands farthest from the center of the magnetotail in directions perpendicular to the solar wind magnetic field. www.agu.org /revgeophys/kivels00/node3.html   (1118 words)

ESA Science & Technology: Cluster reveals the natural scale of the Earth's bow shock thickness The thickness of the Earth's bow shock is proportional to the gyroradius of ions, according to a large set of observations from the Cluster satellites. Shocks are indeed present in coronal, interplanetary, supernova remnants (for example the Cygnus Loop), and heliospheric media. As explained in the December 31 paper, for each bow shock crossing, measurements of a spacecraft floating potential, on the four Cluster spacecraft, have been used as a proxy for electron plasma density. sci.esa.int /science-e/www/object/index.cfm?fobjectid=35500   (547 words)

Bow Shock Epansion - K. Tsubouchi, et al. These studies proved that the shape and size of the bow shock is governed by the upstream solar wind condition, specifically the dynamic pressure and the Mach number (sound, Alfvén, or magnetosonic one). The interplanetary shock at 11:25 UT on Oct. 18 (Terasawa et al., 1996) is driven by this magnetic cloud (Gosling, 1993; Gosling et al., 1994). The difference of the bow shock expansion sense refered above seems to be attributed to the difference of the observing positions between IMP-8 and GEOTAIL; the orbit of IMP-8 was nearly along the shock normal at the dusk side (Figure 1 of Lepping et al. www-ssc.igpp.ucla.edu /IASTP/65   (1888 words)

SPACE.com -- A Glowing Discovery at the Forefront of Our Plunge Through Space After all, the shock wave -- called the "bow shock," like the ripple of water raised by a boat's bow as it moves through the water -- is the solar system's protective womb, and we'd like to know more about it. The solar particles at the edge of the heliosphere form the bow shock, which acts as a barrier to deflect incoming cosmic rays that are up to a million times more energetic than the solar wind. The termination shock is a region where the solar wind first feels the interstellar medium, dropping its speed from several hundred kilometers per second to less than half that. www.space.com /scienceastronomy/solarsystem/heliosphere_shock_000315.html   (1075 words)

UCR Space Physics A bow shock is a shock wave formed ahead of an obstacle in a supersonic flow. Also, the bow shock is "collisionless," owing to the collisionless nature of the solar wind (a). A collisionless shock is one that occurs in a plasma so tenuous that collisions between charged particles are exceptionally rare and have no significant effect on the formation of the shock or the dissipation of kinetic energy in the plasma. spacephysics.ucr.edu /index.php?content=solar_wind/sw/swq5.html   (1022 words)

Glossary Bow shock --a sharp front formed in the solar wind ahead of the magnetosphere, marked by a sudden slowing-down of the flow near Earth. Crab nebula --a cloud-like nebula observed in the Crab constellation, the remnant of a supernova explosion observed in China in 1054. As the magnetosheath plasma streams away from the bow shock, it gradually regains its former velocity. www-spof.gsfc.nasa.gov /Education/gloss.html   (5877 words)

Bows Eye - Wireless Hunting Video Systems Bows Eye allows you to record your hunt without the problems normally associated with mounting a camcorder on a tree or having another person along on your hunt. The Bows Eye Bow Camera mounts to your bow using the stabilizer mount. Bows Eye mounts to the bow itself, not the stabilizer. www.bowseye.com /faqs.html   (914 words)

HD AND MHD EQUATIONS ACROSS BOW SHOCK AND ALONG BOUNDARY SURFACES The position and shape of the bow shock is such as to allow all of the shocked fluid to flow between the shock and the obstacle. Instead, assumptions and approximations are used to estimate the curvature of the shock front, the form of the stream functions, and the vorticity and distribution of pressure downstream from the shock. is the distance from the ellipsoid focus to the shock subsolar position (it is also noted that the average radius of curvature of the obstacle is an important parameter in the placement of the bow shock (see Farris and Russell (1994) for explicit relations between the radius of curvature, obstacle eccentricity, and obstacle standoff distance)). www-ssc.igpp.ucla.edu /personnel/russell/papers/theory   (2039 words)

SPACE.com -- A Glowing Discovery at the Forefront of Our Plunge Through Space After all, the shock wave -- called the "bow shock," like the ripple of water raised by a boat's bow as it moves through the water -- is the solar system's protective womb, and we'd like to know more about it. The solar particles at the edge of the heliosphere form the bow shock, which acts as a barrier to deflect incoming cosmic rays that are up to a million times more energetic than the solar wind. The termination shock is a region where the solar wind first feels the interstellar medium, dropping its speed from several hundred kilometers per second to less than half that. space.com /scienceastronomy/solarsystem/heliosphere_shock_000315.html   (1154 words)

2002 News Releases - Hubble Eyes Bow Shock Near a Young Star The filamentary emission has a distinct boundary on the side facing away from LL Ori, but is diffuse on the side closest to the star, a trait common to many bow shocks. A second, fainter bow shock can be seen around a star near the upper right-hand corner of the image. Astronomers have identified numerous shock fronts in this complex star-forming region and are using this data to understand the complex phenomena associated with star birth. www.jpl.nasa.gov /releases/2002/release_2002_55.html   (334 words)

IMP8 BOW SHOCK CROSSINGS ATTRIBUTES Output from this interface is one line per bow shock crossing containing parameters selected in the left-most boxes and with parameters satisfying any user-specified ranges on the right side. Inferred crossing, data but no likely shock visible When a bow shock crossing is inferred to have happened during some time interval, the start time of the interval is given in the record. Word 39 increments by sum of number of shocks in the interval or one less if the ending shock is also given a separate record of its own. nssdc.gsfc.nasa.gov /ftphelper/bowshock1.html   (995 words)

Bow shock [Oulu]   (Site not responding. Last check: 2007-10-15) This shock wave develops because the information needed to deflect the solar wind plasma around the obstacle travels at a velocity that is less than that of the solar wind flow. In the upstream region, i.e., in front of the bow shock, is the so-called foreshock region. Other waves are generated by electrons and ions accelerated at the bow shock and reflected back into the solar wind or leaked from the magnetosheath back upstream. www.oulu.fi /~spaceweb/textbook/bowshock.html   (454 words)

Earth's Bow Shock: Origin of Ion Beams Revealed The shock transition is clearly visible as the rapid change in the magnetic field in the upper panel. The shock ramp (center) is filled with gyrating ions, from which the distribution extends into the parallel velocity region that is occupied by the beam further upstream. At least in this low Mach number shock, leakage of thermalized ions from the downstream region apparently cannot be the source, as the volume in velocity space occupied by beam ions is empty downstream of the shock. www.spacedaily.com /news/earth-magnetic-04e.html   (1727 words)

Saturn :: Introduction The purpose of this project is to study this shock as it forms around the planet Saturn. Planetary bow shocks accelerate charged particles using a variety of mechanisms that might loosely be compared to simple reflection. Although the Voyagers are not equipped to measure beams of energetic electrons of the type produced by planetary bow shocks, they are equipped to measure the electrostatic waves produced by the electrons. www-ssg.sr.unh.edu /mag/Charter/Saturnshockloc/intro.html   (452 words)

Rock Around the Bow Shock: Cluster Data Sonification As a jet produces the audible supersonic boom, a loud shock wave (to be heard after the jet has passed already the observer’s position), the Earth’s Magnetosphere produces the equivalent structure, the so-called Bow Shock, in the solar wind. Such shock waves are formed in many places in the universe with violent motion, around planets, at the Sun, around the solar system where the solar wind is stopped, and where supernovae blast into their neighborhood. The composition "Rock Around the Bow Shock" has been computer-generated from data obtained during several consecutive crossings of the Cluster spacecraft through the Bow Shock. www-ssg.sr.unh.edu /tof/Outreach/music/cluster/index.html   (681 words)

Theses from Uppsala University : 6123 - Dissipation at the Earth's Quasi-Parallel Bow Shock The Earth's bow shock is a boundary where the solar wind becomes decelerated from supersonic to subsonic speed before being deflected around the Earth. This thesis presents measurements by the Cluster spacecraft upstream and at the Earth's quasi-parallel bow shock where the angle between the upstream magnetic field and the bow shock normal is less than 45 degrees. An intrinsic feature of quasi-parallel shocks is the ability of ions, that are reflected off the shock in a specular manner, to propagate far upstream and to interact with the incident solar wind. publications.uu.se /theses/abstract.xsql?dbid=6123   (660 words)

Termination shock - Wikipedia, the free encyclopedia In space physics, the termination shock is the boundary marking one of the outer limits of the sun's influence. The termination shock boundary fluctuates in its distance from the sun as a result of fluctuations in solar flare activity, i.e. Going outward from the sun, the termination shock is followed by the Heliopause where solar wind particles are stopped by the interstellar medium, then the Bow Shock past which particles from the interstellar medium are no longer excited. en.wikipedia.org /wiki/Termination_shock   (570 words)

Spaceflight Now | Breaking News | Bow shock near a young star The surface where the two winds collide is the crescent-shaped bow shock seen in the image. A second, fainter bow shock can be seen around a star near the upper right-hand corner of the Heritage image. Astronomers have identified numerous shock fronts in this complex star-forming region and are using this data to understand the many complex phenomena associated with the birth of stars. spaceflightnow.com /news/n0203/07hubble   (683 words)

Fast Mode Nature of Earth's Bow Shock Figure 13.4: Crossing of Earth's bow shock in a region where the shock is quasi-perpendicular and supercritical [Schopke et al., 1983]. The figure demonstrates that Earth's bow shock is a fast mode shock, as well as showing the presence of gyrating ions in the shock's foot. Because the plasma is slowed, heated, compressed (ruling out an intermediate/Alfven shock), and the magnetic field is increased in strength and changed in direction (ruling out a slow mode shock). www.physics.usyd.edu.au /~cairns/teaching/lecture13/node3.html   (448 words)

Basic Physics of the Bow Shock One basic difference between solitons and shocks is that shock transitions depend intrinsically on dissipation and an increase in energy across the shock, contrary to the situation for solitons. That is, the standoff distances for the magnetopause and bow shock (and by extension their transverse scales) vary as is that the bow shock is almost always moving; it is a dynamic object. www.physics.usyd.edu.au /~cairns/teaching/lecture13/node2.html   (663 words)

The Bow Shock The spacecraft was well outside the nominal position of the distant bow shock as inferred from the fit of Greenstadt et al. The previous data on the distant bow shock surface are those of Greenstadt et al. The new shock models, based on the insights provided by the Venus flyby, are consistent with the properties of MHD (magnetohydrodynamic) perturbations. www.agu.org /revgeophys/kivels00/node9.html   (538 words)

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