Lightning on Earth, as Seen from the Space Shuttle Discovery

Despite the fact that they have radio communications with Earth, I wonder if, for even a second, these astronauts wondered if perhaps it wasn't lightning.




Which makes me think....if there were some kind of global thermonuclear event / famine / virus, the half-dozen astronauts in the International Space Station would be the only survivors. But for how long? I wonder if NASA / the military has a contingency plan for this scenario...How long can the space station support life without resupply?

Uh, Happy Valentine's Day, Earth! Best of luck!