4K HD Wallpaper: NASA Space Launch System
This 4K image from NASA is one of the coolest featured until now in gallery. Download if you like from here optimized for fit on your desktop backgrounds and homescreen phones.
Widescreen Desktop / Macbook (Retina): 2880x1800 (fits on: 2560x1600, 1920x1200, 1440x900)
High Definition HD 1080p: 1920x1080 (fits on: 1600x900, 1366x768, 1280x720)
Samsung Galaxy Tab & iPad: 2048x2048 (compatible with almost all tablets)
HTC, Samsung Galaxy & iPhone: 1080x1920 (compatible with many smartphones)