The blue sky is the visible part of the Earths atmosphere when the suns light is scattered by the tiny molecules of air in the atmosphere. Blue light is scattered more than other colors because it travels as shorter, smaller waves, which is why we see a blue sky most of the time. It is important to note that the term "Blue Sky" can also refer to a social media platform called Bluesky, which is a decentralized, invite-only social network built on an open-source protocol.