The spirit soul is a minute particle within the body. We cannot see it. One practices the yoga system to raise the soul to the topmost part of the head. This practice goes on while one is living, and the perfection is reached when one can place himself on the top of the head and then break through. Then he can transfer himself to whatever higher planets he likes. That is the perfection of the yogī.
If the yogī is inquisitive to see the moon, he can say, "Ah, let me see what the moon is like. Then I shall transfer myself to higher planets," just like travelers who go to Europe, California, Canada, or other countries on earth. One can transfer oneself to many planets by this yoga system, but anywhere he goes he will find visa systems and customs systems. To go to other planets, one must be qualified.
Kṛṣṇa conscious persons are not interested in any temporary planet, even if it offers a long duration of life. If the yogī, at the time of death, can pronounce oṁ, the concise form of transcendental vibration, and at the same time mām anusmaran, remember Kṛṣṇa, Viṣṇu, he will attain perfection. The purpose of the entire yoga system is to concentrate the mind on Viṣṇu. Impersonalists imagine that they see the form of Viṣṇu, or the Lord, but those who are personalists do not imagine this—they actually see the form of the Supreme Lord. Either way, if one concentrates his mind through imagination or if one actually sees, one has to concentrate his mind on the Viṣṇu form. Mām means "unto the Supreme Lord, Viṣṇu." Anyone who leaves this body and concentrates his mind on Viṣṇu enters into the spiritual kingdom after quitting his body. Those who are actually yogīs do not desire to enter any other planet because they know that life is temporary on the temporary planets, and thus they are not interested. That is intelligence.
Those who are satisfied with temporary happiness, temporary life and temporary facilities are not intelligent according to Bhagavad-gītā (7.23). Antavat tu phalaṁ teṣāṁ tad bhavaty alpa-medhasām: "One whose brain substance is very meager is interested in temporary things." That is the version of Śrīmad Bhagavad-gītā. I am eternal, so why should I be interested in nonpermanent things? Who wants nonpermanent existence? No one wants it. If we are living in an apartment and the landlord asks us to vacate, we are sorry, but we are not sorry if we move to a better apartment. This then is our inclination. We do not wish to die, because we are eternal.
The material atmosphere is robbing us of our eternality. The Śrīmad-Bhāgavatam says, "Our duration of life is being diminished by the sun, beginning from its rising until the time it sets." Daily we are losing the duration of our lives. If the sun rises at 5:30 in the morning, at 5:30 in the evening twelve hours have been taken away from the duration of our lives. We will never get this time back. If we ask any scientist, "I will give you twelve million dollars—please give me back these twelve hours," he will reply, "No, it is not possible." The scientist cannot do it. Therefore the Bhāgavatam says that from sunrise to sunset the duration of our lives is being diminished.