Terminator!

I bet you thought of that badass ultra-lethal robo'. Well, this post is not about him. It's about solar terminator - which is not half as deadly - but it is big. It's really big. Big as Earth, as a matter of fact.
So, solar terminator or twilight zone is acutally an imaginary line that separates the illuminated day side of planetary body from dark night side of a body.
I will not go into details, as always, because I want it to be suitable and understandable for all ages. Links below are for more information, if anyone is interested.

The grey line

Looks awesome from space, I know.


NOAA - Terminator article on NOAA
Terminator - And on Wikipedia.