You must have seen and obsessed over pictures of Northern Lights at least once in your lifetime.
And if you can't really put an image to the image, here
Northern Lights is a common name for Aurora Borealis, which is a natural light display seen prominently on high altitudes of Arctic and Antarctic regions.
Aurorae are caused by cosmic rays, solar wind and magnetospheric plasma interacting with the upper atmosphere (thermosphere/exosphere). Their charged particles, mainly electrons and protons, enter the atmosphere from above causing ionization and excitation of atmospheric constituents, and consequent light emissions.
Basically they are really pretty, and
Recently a NASA astronaut captured footage of the Northern Lights from the international space station.
And it's more beautiful than you could possibly imagine.