An impeller (also written as impellor or impellar) is a rotor used to increase (or decrease in case of turbines) the pressure and flow of a fluid. An impeller for a dam turbine generator.
The smallest planet in the Solar System is Mercury (the biggest planet is Jupiter). For the longest time, the smallest planet was considered to be Pluto, but now Pluto isnât a planet any more, so weâre back to Mercury.Mercury measures 4879 km along its equator.Just for comparison, Earth is 12,742 km across.So Mercury is only 38% the diameter of Earth.or the longest time, the smallest planet was considered to be Pluto, but now Pluto isnât a planet any more, so weâre back to Mercury. Mercury measures 4879 km along its equator. Just for comparison, Earth is 12,742 km across.
Mercury is the smallest actual planet of the eight  comprising the solar system. It is actually smaller (but more  massive) than the moons Ganymede and Titan. Mercury has ab â¦ out 5.5%  of the mass of Earth.    Previously, the dwarf planet Pluto was considered the smallest  planet.ercury is the smallest of the 8 major planets with about 5.5% of the mass of Earth. It is smaller but more massive than the largest moons of Jupiter and Saturn.