Next evolution is explained in the Bhagavad-gītā. You read carefully. What is that evolution? Yānti deva-vratā devān (BG 9.25). Now the next evolution is, if you want to go to the higher planetary system, you can go. But they cannot know, they do not know what are these higher planetary systems. They, we see, every night, there are so many planets, stars, but from the śāstra we can understand that the higher planetary system means the material comforts available there, many, many times more than in this planet. You live in this planet, at most, for one hundred years. But in the higher planetary system you can live which you cannot calculate. Just like Brahmā's life, as stated in the Bhagavad-gītā: sahasra-yuga-paryantam ahar yad brahmaṇo viduḥ (BG 8.17). Brahmā's twelve hours even you cannot calculate with your mathematical figures. But one has to die. Nobody can live permanently within this..., even if you have got a long duration of life.
Higher planetary system means
From the śāstra we can understand that the higher planetary system means the material comforts available there, many, many times more than in this planet.