I have a 5K computer display (5120×2880). Even “high-resolution” desktop wallpaper images stop at 2560 wide… just half the pixels I have to play with. Fortunately, there are many astronomy images available that are not only as big as my display but even far bigger, and I really love astronomy stuff.
Here are two good sources of large and spectacular astronomy photos, with downloads in wide range of sizes, including 10-20,000 pixel wide monsters.
- European Southern Observatory
- HubbleSite (a large, confusing site: I recommend browsing photos in the “entire collection” view)
I should also mention the very simple “Astronomy Photo of the Day” website. It has had a neat picture every day, with a short explanation, practically since the beginning of the Internet. (Well, since June 16, 1995 anyway. They are really not organized at all. It’s just a humungous list of pages.) Not all of the APOD photos are available in large sizes, but many are.
I have many favourites. Here’s just one that I particularly love: