U ntil we live in a world based purely on sliding doors, door hinges will remain some of the most unsung heroes of our society. We'd still be able to saunter through door frames, ...

Asteroid 2004 GU9 is now known as Cardea, one of the Roman deities of doors and thresholds with a particular focus on hinges. Cardea is not a real satellite of our planet like the Moon – it is not ...