This might look like some weird cosmic gateway straight out of 2001: A Space Odyssey or a particularly trippy old-school Doctor Who adventure, but the Red Square Nebula is completely real. Just don't ask astronomers to explain its bizarre shape.
Even if its name sounds downright un-American, the Red Square Nebula has got to be my new favorite celestial phenomenon, if only because it looks so ridiculously like something out of vintage science fiction, as you can see in this image created from various infrared exposures from Earth-based telescopes in Hawaii and California. Part of the reason the nebula looks so unreal is its unique square structure, for which astronomers still have no obvious explanation.
The leading hypothesis is that the star or stars at the heart of the nebula for some reason expelled unusual cones of gas at a late stage in their development, and these just happened to form a square-like shape. Sure, "for some reason" and "just happened" aren't the most scientific argument ever, but that's the thing about the universe - it's so big that plenty of things can quite comfortably happen completely by chance.
Of course, we only see it like a square because that's the shape that happens to be turned toward us at precisely the right angle to create this effect. The Red Square Nebula would look very different from other angles, and astronomers speculate that viewed from other angles its cones would look like the huge rings that we can observe on supernova 1987A, which suggests that a star inside this nebula is someday headed for a fierce supernova all its own.