Scientists detect weather on distant planet

Weather patterns in a “mysterious” world beyond the solar system have been revealed for the first time, by Scottish scientists.

Artist's impression of the planet-like object PSO J318.5-22, as clouds made of droplets of molten iron have been detected on the sunless world 75 light years from Earth.Picture: MPIAV.Ch.Quetz/University of Edinburgh/PA Wire

Layers of clouds, made up of hot dust and droplets of molten iron, have been detected on a planet-like object found 75 light years from Earth.

The findings could improve scientists’ ability to discover if conditions in far-off planets are capable of sustaining life, astronomers from the University of Edinburgh suggest.

The team used a telescope in Chile to examine the weather systems in the distant world – known as PSO J318.5-22 – estimated to be 20 million years old.

Researchers captured hundreds of infra-red images of the object rotating over five hours.

By comparing the brightness of PSO J318.5-22 with neighbouring bodies, the team discovered that it is covered in multiple layers of thick and thin cloud.

These cause changes to the brightness of the distant world as it rotates, the team said.

The far-off world is around the same size as Jupiter – the largest planet in our solar system – but is roughly eight times more massive. Temperatures inside clouds on PSO J318.5-22 exceed 800°C, researchers said. The team were able to accurately measure changes in brightness on PSO J318.5-22 because it does not orbit a star.

Stars like our Sun emit huge amounts of light, which can complicate measurements made of the brightness of objects orbiting them. The team hopes to adapt the technique so they can study planets that do orbit stars.

Such techniques may eventually be applicable to cooler, lower-mass planets, which are more likely to be capable of supporting life, researchers say.

Dr Beth Biller, of the university’s school of physics and astronomy, who led the study, said: “This discovery shows just how ubiquitous clouds are in planets and planet-like objects.

“We’ve seen similar weather patterns in brown dwarfs (objects too big to be called planets and too small to be stars) and gas giants in our solar system such as Jupiter and Saturn.

“We’re working on extending this technique to giant planets around young stars, and eventually we hope to detect weather in Earth-like exoplanets that may harbour life.”

The study is published in The Astrophysical Journal.