The sky on planets with a different atmospheric composition would appear to be a different color. A solid is a phase of matter in which the molecules are very close together and cannot move around. Stishovite is a very dense form of quartz that has only been found in meteorite impact craters, in which quartz has undergone high-pressure shock. A stratovolcano is a composite volcano . The descending crust melts as it is pushed deep into the Earth's mantle .
Subduction destroys crust and recycles it back into the mantle.
A subduction zone is an area on a planet's crust in which the edge of an oceanic continental plate is being pushed beneath another plate. As stated in our privacy policy , we fully respect your privacy and will not use your e-mail address for any purpose other than the newsletter subscription.