So this transmigration of soul is the most important factor to be understood by the human society. Unfortunately, there is no university, there is no department of knowledge to understand this important factor. That is very risky.
So this soul is transmigrating from one body to another, and there are 8,400,000 species of life, and our . . . after leaving this body we may accept any one of them. We do not know. That will depend on our action at the present moment. Practically we are preparing our future body, and according to our work and mentality, we get a different body.
Therefore we shall be very much cautious. Any intelligent man can understand that the future life is prepared at present. Just like the boy goes to the school, goes to the college, he prepares his future life, similarly, this human form of life is a preparation ground for our future life.
So according to Bhagavad-gītā, we can transfer to other planets also. This is explained in our book Easy Journey to Other Planets. The present endeavor is to transfer one to the moon planet. But as we get information from the Vedic literature, we cannot transfer ourself by mechanical arrangement to the moon planet. That is not possible. This is futile attempt.
Every planet has got different atmosphere. So in order to enter into a particular planet we have to prepare ourself. This is also understandable very easily. Just like if we go to a foreign country we have to prepare for visa and passport. If in this planet also we are so much restricted, how foolishly we are attempting to go to other planet without being prepared for entering that planet.