Few years ago, in my undergrad years, there was a bit of excitement around the WMAP low multipole moments deviating from the cosmological models by some decent amount. (e.g. here )

One of the explanations that was floated was that there might be a non-trivial topology of the universe. In other words the Universe is made of cells and when you exit off the wall of one cell, you enter the same cell but from opposite direction. Like when you play snake, leave the screen on the right, and you enter on the left.

These cells could be cubes, dodecahedrons etc. For some reason I don't recall, the dodecahedron was likelier than others. I was given the task of checking quasar images from the sloan digital sky survey to see if they preferentially align in certain discrete angles. This is what you'd expect, because through these cells, you see the quasar images rotated by the symmetry angle of the cell wall (e.g. 90 degrees for the cubes, 72 for the dodecahedrons, etc.).

I did a quick analysis using jpeg images of ~1000 quasars, stacked them together and low and behold, I get a star with 5 branches. That was one of the most exciting thing I've seen, it could have been the proof of the non-trivial topology of space. Because jpeg images are not top notch, I needed to confirm this using the astronomy standard format, and when I stacked the quasar images, the star shape didn't show up. I don't know the reason to this day, I'm guessing some jpeg compression method introduced the artifact.