A Brave New World - Planet Matte Painting / Sphere Projection

I decided to sharpen my matte painting skills by trying out something interesting but difficult - painting an original planet.
What do you think - how do you think I could improve?

First, I rendered a sphere from Blender to use as my base.

Next, I extracted clouds, land masses and city lights from photos taken from the International space Station.

I arranged/blended all of these photo elements on top of my sphere using Photoshop.

The final result was then projected back onto my sphere inside of Blender (that way, I can animate a simple camera pan animation).

Good matte! m8!

This is amazing man!! I have a question about painting, I can’t figure out how to fix the triangular “pinching” at the poles of my planets and export an actual equirectangular map. any advice?