Back in 2013 a rather strange object was found floating in space, around 75 lightyears out, and it was called PSO J318.5-22. From the press release from the University of Hawaii:
An international team of astronomers has discovered an exotic young planet that is not orbiting a star. This free-floating planet, dubbed PSO J318.5-22, is just 80 light-years away from Earth and has a mass only six times that of Jupiter. The planet formed a mere 12 million years ago—a newborn in planet lifetimes.
It was identified from its faint and unique heat signature by the Pan-STARRS 1 (PS1) wide-field survey telescope on Haleakala, Maui. Follow-up observations using other telescopes in Hawaii show that it has properties similar to those of gas-giant planets found orbiting around young stars. And yet PSO J318.5-22 is all by itself, without a host star.
“We have never before seen an object free-floating in space that that looks like this. It has all the characteristics of young planets found around other stars, but it is drifting out there all alone,” explained team leader Dr. Michael Liu of the Institute for Astronomy at the University of Hawaii at Manoa. “I had often wondered if such solitary objects exist, and now we know they do.”
During the past decade, extrasolar planets have been discovered at an incredible pace, with about a thousand found by indirect methods such as wobbling or dimming of their host stars induced by the planet. However, only a handful of planets have been directly imaged, all of which are around young stars (less than 200 million years old). PSO J318.5-22 is one of the lowest-mass free-floating objects known, perhaps the very lowest. But its most unique aspect is its similar mass, color, and energy output to directly imaged planets.
Follow-up information from the University of Edinburgh is now available:
Weather map of distant world revealed
Weather patterns in a mysterious world beyond our solar system have been revealed for the first time, a study suggests.
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, researchers say.
Findings from the study could improve scientists’ ability to find out if conditions in far-off planets are capable of sustaining life.
Cloud cover
University researchers used a telescope in Chile to study the weather systems in the distant world – known as PSO J318.5-22 – which is estimated to be around 20 million-years-old.
They captured hundreds of infra-red images of the object as it rotated over a 5-hour period.
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.
No star, yet so hot, suggests internal heating. Must be nuclear. Fascinating!
