This is a still from an animation showing asteroid 2024 YR4 as it passes by Earth and heads toward its potential impact with the Moon. This 3D shape of the asteroid was determined from data obtained ...

In the case of our 'string around the Earth' puzzle, the radius is being increased by 15cm, so we need to know that as a fraction of the original radius. So what is the radius to start with?

We’ve produced a series of puzzles, animated videos ... and how it has led to the astonishing diversity of life on Earth. And if you’re among the many people who are confused by common ...