The impeller made out of cast material in many cases may be called rotor, also. It is cheaper to cast the radial impeller right in the support it is fitted on, which is put in motion by the gearbox from an electric motor, combustion engine or by steam driven turbine.
Earth remains the only known planet to host life, due to a unique combination of factors. However, continued monitoring of alien worlds might one day change that, by finding other planets that share these attributes or by discovering other ways that life has found to blossom in the universe.
Similarly, Mars has a high temperature of 98 degrees Fahrenheit at its equator and a low temperature of -190 degrees at its poles. The Earth's average surface temperature is 45 degrees, while Venus has an average surface temperature of 850 degrees. Mercury, Venus, Earth and Mars are the inner planets.