Brainstorming for Moon & Stars Boy Nursery

Lisadi

 I'm just starting to plan a nursery for DS#2. I'm afraid to make it "too cool" in the eyes of DS#1 as I (1) don't want him to get extra jealous and (2) don't want to update DS#1's room. So, some fun themes like fire trucks and dalmatian dogs will be out.
 Also, I'd like the room to be able to grow with him, and not be too baby-like.

 I'm leaning towards a moon and star nursery. I've been on Pinterest, but could use a few more ideas. For example, if I wanted to tie in other themes, I could use a picture from the book "Goodnight, Goodnight Construction Site" without going all out on the truck theme. Can anyone think of any others?
 Also, I'm passing on a bedding set, and will just piece it together based on color and comfort.

 Here are a few of my ideas:
 - Decal ideas:
      - https://www.houzz.com/photos/44573/modern-blue-orange-nursery-spaces-other-metro
     - https://www.etsy.com/listing/95080096/baby-nursery-wall-decal-moon-stars-and?utm_campaign=Share&utm_medium=PageTools&utm_source=Pinterest

 - Moon/Star shaped mirrors: https://www.mirrormaniac.co.uk/moon-shaped-mirror-352-p.asp
 - Mobile/Nightlight: https://thepeeleffect.tumblr.com/post/3312518591
 - Nightlight: https://www.toysrus.com/product/index.jsp?productId=3819669&CAWELAID=427070777&cagpspn=pla&pla=plab&camp=PLAPPC-_-PID6747542&KPID=6747542

 - Related themes to add: telescope, globe, shooting stars, clouds (maybe even 'images' in clouds in night sky), spaceships, solar system (maybe wait to add until older to add the solar system... And, I know there's no guarantee we won't change this earlier. But, I'd like to get my mileage out of it vs. redoing a room every few years.)

 Any other ideas greatly appreciated!