Dhruvaloka, our polestar, is the center for all other stars and solar systems, for all of them circle around Dhruvaloka just as a bull crushes grains by walking around and around a central pole
SB Canto 4
The Supreme Personality of Godhead continued: My dear Dhruva, I shall award you the glowing planet known as the polestar, which will continue to exist even after the dissolution at the end of the millennium. No one has ever ruled this planet, which is surrounded by all the solar systems, planets and stars. All the luminaries in the sky circumambulate this planet, just as bulls tread around a central pole for the purpose of crushing grains. Keeping the polestar to their right, all the stars inhabited by the great sages like Dharma, Agni, Kaśyapa and Śukra circumambulate this planet, which continues to exist even after the dissolution of all others.
Although the polestar existed before its occupation by Dhruva Mahārāja, it had no predominating deity. Dhruvaloka, our polestar, is the center for all other stars and solar systems, for all of them circle around Dhruvaloka just as a bull crushes grains by walking around and around a central pole. Dhruva wanted the best of all planets, and although it was a childish prayer, the Lord satisfied his demand. A small child may demand something from his father which his father has never given to anyone else, yet out of affection the father offers it to the child; similarly, this unique planet, Dhruvaloka, was offered to Mahārāja Dhruva. The specific significance of this planet is that until the entire universe is annihilated this planet will remain, even during the devastation which takes place during the night of Lord Brahmā. There are two kinds of dissolutions, one during the night of Lord Brahmā and one at the end of Lord Brahmā's life. At the end of Brahmā's life, selected personalities go back home, back to Godhead. Dhruva Mahārāja is one of them. The Lord assured Dhruva that he would exist beyond the partial dissolution of this universe. Thus at the end of the complete dissolution, Dhruva Mahārāja would go directly to Vaikuṇṭhaloka, to a spiritual planet in the spiritual sky. Śrīla Viśvanātha Cakravartī Ṭhākura comments in this connection that Dhruvaloka is one of the lokas like Śvetadvīpa, Mathurā and Dvārakā. They are all eternal places in the kingdom of Godhead, which is described in the Bhagavad-gītā (tad dhāma paramam) and in the Vedas (oṁ tad viṣṇoḥ paramaṁ padaṁ sadā paśyanti sūrayaḥ). The words parastāt kalpa-vāsinām, "transcendental to the planets inhabited after the dissolution," refer to the Vaikuṇṭha planets. In other words, Dhruva Mahārāja's promotion to the Vaikuṇṭhalokas was guaranteed by the Supreme Personality of Godhead.