The northern lights are brighter this year. Scientists explain why
Solar activity is peaking, and a quieter sky is letting more of us see it.
The summer the festivals came back louder than ever
Bigger crowds, smaller stages and a new generation of fans who want to be in the room.
The cycling boom is reshaping how cities plan their streets
Painted lanes were the start. Now planners are redesigning whole neighbourhoods around the bike.
Fjords without the crowds: the slow way through Norway
Skip the cruise ships. Ferries, trains and a borrowed kayak tell a better story.
The megacity census: who really lives in the world’s biggest cities
Official counts miss millions. A new survey tries to find them.