Our strategy for Angry Birds Space Cosmic Crystals level 7-13 is to cause the center planet to detonate. In the video, the rocket ship is pushed into the gravitational field, though there’s a detonator to the northeast of the planet that will set off the TNT. After the chaos, target the north planet if necessary. The score in the video below is 89,210.
The video below shows the hidden detonator. Though the scoring is approximately the same, the strategy below may be easier to reproduce. The score in the video below is 86,880.