Atmosphere of Earth sublimated into polar-mesospheric noctilucent clouds. These are the highest clouds in the atmosphere and may be visible to the naked eye if sunlight reflects off them about an hour or two after sunset or a similar length of time before sunrise. They are most readily visible when the Sun is around 4 to 16 degrees below the horizon. Lightning-induced discharges known as transient luminous events (TLEs) occasionally form in the mesosphere above tropospheric thunderclouds. The mesosphere is also the layer where most meteors burn up upon atmospheric entrance. It is too high above Earth to be accessible to jet-powered aircraft
What Where the metallic floor accentuate the chilly atmosphere. O'Donnell said in interview: "[T]here is no set in the original play, but I argued that the whole play is about power and the abuse of power, and how information is power, so we used the library as a metaphor for somebody who has control of all the power and all the information. When it came to casting, I was looking for a particular type of actor – somebody who could bring a sort of menacing quality to the screen. There is a lot of menace in the play. "What Where" is about