The planet Ventax II had east and west magnetic poles. (TNG: "Devil's Due" ) Tyrellia was an inhabited planet located within the Federation's sphere of influence, known for being only one of three such planets to lack a magnetic pole and one of only seven without any kind of atmosphere. (TNG: "Starship Mine" ) While attempting to extract their away team from Augris' species planet in 2372, the USS Voyager hid within a large magnetic storm over the planet's northern magnetic pole to avoid the phased ion cannons of the Mokra Order. (VOY: "Resistance")