Occurrence of Shock Waves in Space Environments

Supernova explosions produce spherical shock waves with stellar remnants. The shock wave propagates into interstellar space and dynamically interacts with the ambient interstellar clouds. Yusef-Zadeh et al. [48] reported that shock-excited OH maser emission outlined the galactic center supernova remnant. Aschenbach et al. [49] suggested that the X-ray emission associated with the ejected objects was produced by shock heating of the ambient medium resulting from supersonic motion of the objects. 

Formation of Planetesimals and Meteorites from Grains in Interstellar Clouds 

Gases and grains in interstellar clouds probably experienced many shock events during the formation of planetesimals and meteorites. These events are as follows 1) coagulation of dust into clumps, which settle to the equatorial plane of the nebula 2) breakup of the gravitationally unstable dust disk into clusters of dust clumps 3) coalescence of the clusters into 1 km planetesimals  

4) collision of the planetesimals during the accretion of meteorite parent bodies  

5) collision of the parent bodies after their formation. These events induce strong shock waves. The shock waves would cause chemical and physical transformations of materials during these events. In particular, the last three events are characterized by hypervelocity impact, and cause shock metamorphism and impact-induced breccia formation on the parent bodies and on meteorites. These 

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