The IAU has so far recognized five dwarf planets differentiated from planets by a parameter of "planetary discriminant" which allows estimating the capacity to dominate orbits. According to NationMaster Encyclopaedia dwarf planets follow orbits which are not free from other minor celestial bodies. Simultaneously, they always circulate the Sun and not other celestial objects (they are not satellites). Several dwarf planets have already been scrutinized effectively. Their physical properties have been calculated through routine Earth-based observations as well as advanced image-searching software. Since current data may not be entirely accurate, further examinations are undertaken by astronomers and physicists world-wide.