Astronomers know that planets around other stars beyond the Solar System are common. But these planets are very hard to see and even harder to study. Fortunately, there is a clever trick that helps to separate the feeble glow of a planet from the dazzling glare of its parent star: exploiting the polarisation of the light reflected from the planet.

In this episode of the ESOcast we'll talk about this very special feature of light and how we can use it to detect planets around other stars.

Credit: ESO