The supplementary motor area (SMA) is a part of the primate cerebral cortex that gives room for the control of their movement. It is located on the midline surface of the hemisphere right in front of (anterior to) the primary motor cortex leg representation.
Earth resembles a "blue marble" when viewed from space primarly due to the presence of water on it's surface. Water cover 70% of the earth's surface but only 2.5 of it is fresh and drinkable.