Planetary structures

Crust: The crust is the planet’s solidified outermost layer. The oldest crust that has not melted again is generally saturated with impact craters. Molten magma rises through fractures and flows over the cratered crust as volcanic lava. Sediments transported from elsewhere may then cover it. Life: Evolution produces distinctive forms, but life is defined by its processes rather than its shape. Life reorganises matter until it becomes aware of its own existence. Love, other emotions and knowledge are characteristic of life alone. Geological unit: A planetary surface is a patchwork of rock units of different ages, materials, shapes, sizes and histories. Units continue below the surface. All the rock in a unit formed together in one geological event. Planet: The largest planetary structure is the planetary body itself. It formed from small grains, melted and assumed the simplest and most beautiful gravitational shape: a sphere, slightly flattened by rotation. Heavier elements sank into its interior. Science: Science gathers knowledge and organises it into a system. New structures in the world emerge as we organise knowledge in new ways. Further information: Tudósok (1993), Mi a tudomány?, Bahia Kiadó.

Landforms: Landforms are distinctive parts of the relief that we, living on the surface, recognise as units. The three basic elements are valleys—or basins when round—plains and mountains. They are the surface boundaries of geological units extending into the interior, shaped by erosion and redistribution of material.