Colliding galaxies and 'Goldilocks' planets: the revolution in astronomy

Cosmologist Jo Dunkley on the most mind-bending recent discoveries, as astronomers use powerful new telescopes to explore nature's weirdest stars, 'dark energy' and the origins of gold

Astronomy is in the middle of a data revolution, a time of enormous discovery. Humans have been looking up at the stars for thousands of years, but modern telescopes and computers are rapidly accelerating our understanding. We know far more than we did even 20 years ago, and we are now much closer to answering questions about whether life exists elsewhere in the cosmos, how our planet came to be here, our cosmic origins and eventual fate.

On a clear night the stars twinkle in the sky, and often we can see the bright planets of our own solar system in orbit, like us, around our sun. Until the early 1990s, we had no idea whether there were any other planets around the stars in the sky. Astronomers suspected so, but had no way to prove it. We have in the past decade found thousands in orbit around foreign stars, and have a better idea of how common they are. A sizable fraction of stars probably have their own planets, their own worlds carried around them in the most fantastically diverse solar systems.