What happens if the sky falls down?
The question does not make sense. Sky is a term used to describe the upward view from the surface of the Earth. It can also be described as the space between Earth’s surface and outer space. Therefore the idea of the sky falling down is absurd. However, the famous idiom “The Sky is falling” refers to panic and mass hysteria.
Instruction: What happens if the sky falls down?
Context: 
Response: The question does not make sense. Sky is a term used to describe the upward view from the surface of the Earth. It can also be described as the space between Earth’s surface and outer space. Therefore the idea of the sky falling down is absurd. However, the famous idiom “The Sky is falling” refers to panic and mass hysteria.