system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: My daughter just asked me “If outer space is black, how is the sky blue?” Help me explain it please.
gpt
For a more ELI5 explanation for your daughter: when the sunlight passes through our air at higher altitude (Non-ELI5: upper atmosphere), it becomes bent at different angles (Non-ELI5: elastic scattering via Rayleigh scattering). The sky is blue during the day because the part of sunlight that bends the most is blue. At night, because there is no sunlight, the sky becomes colourless, and we see the black outer space.

A quick experiment you can do with your daughter is the glass-prism light refraction experiment to split the sunlight into a rainbow of colours. It is not completely correct (because refraction and Rayleigh scattering are different mechanisms), but it will help your daughter understand how sunlight can bend to produce colours.