Today these lights randomly popped up in the sky. They light up for around 30s-1m, then the disappear for a few seconds and come back again. Seen in Uppsala, Sweden

​

https://preview.redd.it/kvgwbvuaxyp31.jpg?width=816&format=pjpg&auto=webp&s=5fa755e588b7d0348376e7b9f923fc52057c1e50