Tiny crack in steel seen through an electron microscope

Canyon or crack? Crack, obviously, since it's right there in the headline, but isn't it amazing? Especially with clouds photoshopped in to improve its virality coefficient.

There's probably one of these on the plane you just boarded, lurking somewhere the hard-pressed engineers and inspectors might have missed. They have even less time than you do! Metaphorically speaking, of course. Go on, just look out the window, at the wing. Bit of rust around those bolts, eh? Well, they do say that an old, well-maintained plane is safer than a new, badly-maintained one.

If the worst happens, though, and you find yourself plunging into the void of death from 30,000 feet, you can muse over a final flicker of wonderment: maybe in the next life I'll wake up in a tiny canyon.

https://www.youtube.com/watch?v=gO5gPdJxe_o