NASA officials warn thousands of undetected “city killer” asteroids may be circling near Earth. With limited deflection tools ready, are we prepared if one suddenly shifts onto a collision course?

For 42 years, NASA satellites have tracked how sunlight powers Earth’s climate. The long record is revealing subtle shifts that could reshape climate predictions. These findings are adding new layers ...

A British artificial intelligence (AI) researcher is in talks to raise $1bn (£740m) for his three-month-old start-up in what would be one of the biggest ever venture funding rounds in Europe.