I also gave into temptation and created a similar image (but instead used the 2001 Obelisk).
One thing about using such a high-resolution image is that what appears to be grain is actually stars - which in itself is kind of amazing - but a real problem for anything beyond a still image. Those individual and tiny stars will flicker when used in an animation unless you increase your ray counts to obscenely high levels. What you would need to do is to create a blurred copy of that image for the luminance channel but do not enable rendering for that background - here it is just a light source. Over that in the color channel would be the full resolution image but with its illumination values turned way down so that the smallest and dimmest stars completely disappear - thus removing the potential for flickering when being rendered in an animation.
An interesting comment about the 2001 obelisk. In the book, the ratio of its dimensions (to the 6th decimal place) were 1:4:9 - or the squares of 1, 2 and 3. But in the movie, the on-set Obelisk was built as 1.25 x 5 x 11 - which had a ratio of 1:4:8.8.
I will admit that in my own attempts to model the 2001 obelisk it always looked "off" to me. A simple 1:4:9 cube just did not feel right based on what I was trying to copy from the movie. Very frustrated that I could not even model a 1 x 4 x 9 cube and get satisfactory results!!!
Pretty confident that Cerbera and Vector never had days like this.
Well...now I know why.
Dave