f = PN/120 where f is frequency of power supply, P is number of poles in the machine and N = speed in rpm. So, Synchronous speed N = 120f/P. Thus for 50 Hz supply, 2 pole machine; synchronous speed = 3000rpm. ETRICAL
Within our solar system quite a bit of exploration has been done by spacecraft including orbiters and landers. Planets outside our solar system will be difficult or impossible to explore with spacecraft in our lifetimes, so astronomers and astrobiologists use other techniques to search for signs of life on these planets. In particular, astronomers are interested in planets within the habitable zone of stars.
The planet has two small moons called Phobos and Deimos. Beyond Mars are the four outer planets: Jupiter, Saturn, Uranus, and Neptune. We have written many interesting articles about the inner planets here at Universe Today. Hereâs The Solar System Guide as well as The Inner and Outer Planets in Our Solar System.