…The spiritual world, the abode of the Supreme Personality of Godhead, Kṛṣṇa-which is known as Kṛṣṇaloka, Goloka Vṛndāvana-is described here. In the spiritual sky there is no need of sunshine, moonshine, fire or electricity, because all the planets are self-luminous. We have only one planet in this universe, the sun, which is self-luminous, but all the planets in the spiritual sky are self-luminous. The shining effulgence of all those planets (called Vaikuṇṭhas) constitutes the shining sky known as the brahmajyoti. Actually, the effulgence is emanating from the planet of Kṛṣṇa, Goloka Vṛndāvana. Part of that shining effulgence is covered by the mahat-tattva, the material world. Other than this, the major portion of that shining sky is full of spiritual planets, which are called Vaikuṇṭhas, chief of which is Goloka Vṛndāvana.
The abode of Lord Śrī Kṛṣṇa is described in the Bhagavad-gītā, Fifteenth Chapter, sixth verse:
na tad bhāsayate sūryo na śaśāṅko na pāvakaḥ
yad gatvā na nivartante tad dhāma paramaṁ mama
“That abode of Mine is not illumined by the sun or moon, nor by electricity. And anyone who reaches it never comes back to this material world.” (Bg. 15.6)
This verse gives a description of that eternal sky. Of course we have a material conception of the sky, and we think of it in relationship to the sun, moon, stars and so on, but in this verse the Lord states that in the eternal sky there is no need for the sun nor for the moon nor fire of any kind because the spiritual sky is already illuminated by the brahmajyoti, the rays emanating from the Supreme Lord. We are trying with difficulty to reach other planets, but it is not difficult to understand the abode of the Supreme Lord. This abode is referred to as Goloka. In the Brahma-saṁhitā it is beautifully described: Goloka eva nivasaty akhilātma-bhūtaḥ. The Lord resides eternally in His abode Goloka, yet He can be approached from this world, and to this end the Lord comes to manifest His real form, sac-cid-ānanda-vigraha. When He manifests this form, there is no need for our imagining what He looks like. To discourage such imaginative speculation, He descends and exhibits Himself as He is, as Śyāmasundara. Unfortunately, the less intelligent deride Him because He comes as one of us and plays with us as a human being. But because of this we should not consider that the Lord is one of us. It is by His potency that He presents Himself in His real form before us and displays His pastimes, which are prototypes of those pastimes found in His abode.
In the effulgent rays of the spiritual sky there are innumerable planets floating. The brahmajyoti emanates from the supreme abode, Kṛṣṇaloka, and the ānandamaya-cinmaya planets, which are not material, float in those rays. The Lord says, na tad bhāsayate sūryo na śaśāṅko na pāvakaḥ yad gatvā na nivartante tad dhāma paramaṁ mama. One who can approach that spiritual sky is not required to descend again to the material sky. In the material sky, even if we approach the highest planet (Brahmaloka), what to speak of the moon, we will find the same conditions of life, namely birth, death, disease and old age. No planet in the material universe is free from these four principles of material existence. Therefore the Lord says in Bhagavad-gītā, ābrahma-bhuvanāl lokāḥ punar āvartino ‘rjuna. The living entities are traveling from one planet to another, not by mechanical arrangement but by a spiritual process. This is also mentioned: yānti deva-vratā devān pitṝn yānti pitṛ-vratāḥ. No mechanical arrangement is necessary if we want interplanetary travel. The Gītā instructs: yānti deva-vratā devān. The moon, the sun and higher planets are called svargaloka. There are three different statuses of planets: higher, middle and lower planetary systems. The earth belongs to the middle planetary system. Bhagavad-gītā informs us how to travel to the higher planetary systems (devaloka) with a very simple formula: yānti deva-vratā devān. One need only worship the particular demigod of that particular planet and in that way go to the moon, the sun or any of the higher planetary systems.
Yet Bhagavad-gītā does not advise us to go to any of the planets in this material world because even if we go to Brahmaloka, the highest planet, through some sort of mechanical contrivance by maybe traveling for forty thousand years (and who would live that long?), we will still find the material inconveniences of birth, death, disease and old age. But one who wants to approach the supreme planet, Kṛṣṇaloka, or any of the other planets within the spiritual sky, will not meet with these material inconveniences. Amongst all of the planets in the spiritual sky there is one supreme planet called Goloka Vṛndāvana, which is the original planet in the abode of the original Personality of Godhead Śrī Kṛṣṇa. All of this information is given in Bhagavad-gītā, and we are given through its instruction information how to leave the material world and begin a truly blissful life in the spiritual sky. (from Introduction to Bhagavad-gita As It Is)
Bhagavad-gita As It Is 1972 Edition
By His Divine Grace A.C. Bhaktivedanta Swami Prabhupada
Chapter 15, Text 6
The Yoga of the Supreme Person
na tad bhāsayate sūryo
na śaśāṅko na pāvakaḥ
yad gatvā na nivartante
tad dhāma paramaṁ mama
na—not; tat—that; bhāsayate—illuminates; sūryaḥ—sun; na—nor; śaśāṅkaḥ—the moon; na—nor; pāvakaḥ—fire, electricity; yat—where; gatvā—going; na—never; nivartante—comes back; tat dhāma—that abode; paramam—supreme; mama—My.
That abode of Mine is not illumined by the sun or moon, nor by electricity. One who reaches it never returns to this material world.
As long as a living entity is in this dark material world, he is in conditional life, but as soon as he reaches the spiritual sky, by cutting through the false, perverted tree of this material world, he becomes liberated. Then there is no chance of his coming back here. In his conditional life, the living entity considers himself to be the lord of this material world, but in his liberated state he enters into the spiritual kingdom and becomes the associate of the Supreme Lord. There he enjoys eternal bliss, eternal life, and full knowledge.
One should be captivated by this information. He should desire to transfer himself to that eternal world and extricate himself from this false reflection of reality. For one who is too much attached to this material world, it is very difficult to cut that attachment, but if he takes to Kṛṣṇa consciousness, there is a chance of gradually becoming detached. One has to associate himself with devotees, those who are in Kṛṣṇa consciousness. One should search out a society dedicated to Kṛṣṇa consciousness and learn how to discharge devotional service. In this way he can cut off his attachment to the material world. One cannot become detached from the attraction of the material world simply by dressing himself in saffron cloth. He must become attached to the devotional service of the Lord. Therefore one should take it very seriously that devotional service as described in the Twelfth Chapter is the only way to get out of this false representation of the real tree. In Chapter Fourteen the contamination of all kinds of processes by material nature is described. Only devotional service is described as purely transcendental.
The words paramaṁ mama are very important here. Actually every nook and corner is the property of the Supreme Lord, but the spiritual world is paramam, full of six opulences. In the Upaniṣads it is also confirmed that in the spiritual world there is no need of sunshine or moonshine, for the whole spiritual sky is illuminated by the internal potency of the Supreme Lord. That supreme abode can be achieved only by surrender and by no other means.
The Lord descends to this mortal world to show His pastimes in Vṛndāvana, which are full of happiness. When Lord Śrī Kṛṣṇa was in Vṛndāvana, His activities with His cowherd boy friends, with His damsel friends, with the inhabitants of Vṛndāvana and with the cows were all full of happiness. The total population of Vṛndāvana knew nothing but Kṛṣṇa. But Lord Kṛṣṇa even discouraged His father Nanda Mahārāja from worshiping the demigod Indra because He wanted to establish the fact that people need not worship any demigod. They need only worship the Supreme Lord because their ultimate goal is to return to His abode. (From Introduction to Bhagavad-gita )