The next quasi-satellite in the solar system now has an official name. Cardea is a companion of the Earth and was discovered more than 20 years ago.

O ne of Earth’s seven quasi-moons has just got a new name: Asteroid 2004 GU9 is now known as Cardea, one of the Roman deities of doors and thresholds with a particular focus on hinges.

U ntil we live in a world based purely on sliding doors, door hinges will remain some of the most unsung heroes of our ...