The UFO sightings that swept the US

Seventy-five years on from the first mysterious sightings in the US, Nicholas Barber looks back at one of the most haunting objects in popular culture.

Do we need a new theory of evolution?

A new wave of scientists argues that mainstream evolutionary theory needs an urgent overhaul. Their opponents have dismissed them as misguided careerists – and the conflict may determine the future of biology.

5,000 exoplanets now confirmed to exist

Exoplanets, worlds orbiting distant stars, were once only theorized. And even then, astronomers thought only some stars had planets. Yet, on Monday, NASA announced that, to date, 5,000 exoplanets have been detected.