Several organic molecules found outside Earth are not of biological origin, however. The chemical reaction between metals and oxygen in which new compounds are formed. Photodissociation - The breaking up of a molecule due to the action of light. Plate tectonics - The particular tectonic theory that explains the geology of Earth's crust. Earth's crust is divided in mobile sections, moving at the rate of a few centimeters per year.
New crust is formed or destroyed at the boundaries between plates.
In places such as the San Andreas Fault, two plates slide by each other moving in opposite directions. Continents are carried on top of the tectonic plates. Radiating - Warm object radiate energy, i.e. emit it, in the form of infrared light. Infrared radiation is a form of light, invisible to human eye. Rifts - Regions of a planet's crust where the crust is itself being created.