As we reported recently, a stunning new image from New Horizons shows huge mountains and vast valleys of nitrogen ice on the surface of Pluto — but it’s what’s floating above the surface that has really captured scientists attention.

Ever since its July 2015 flyby of the dwarf planet, New Horizons has been sending back data and images at a trickle, and the latest image shows incredible “twilight zone” images of Pluto that allow us to see some incredible detail of the planet. And one particularly fascinating detail appears to be a whisp of methane cloud floating above the Pluto surface, according to a NASA statement.

The backlit twilight view shows sunlight as it filters through the layers of Pluto’s atmosphere, lighting up what appears to be a large cloud floating above the mountain ranges and plains of the surface. The low-lying cloud, which would be made of methane, would be the only one identified through New Horizons imagery.

The picture was taken about 19 minutes after the spacecraft’s closest approach to Pluto, when it was about 13,400 miles from the surface of the dwarf planet.

Pluto doesn’t have a thick atmosphere like ours with large cumulus clouds, but the image definitely depicts a haze in its thin atmosphere. The top of the photo has long, wispy formations that are unmistakably clouds, an amazing sight.

“The inset at top right shows a detail of Pluto’s crescent, including an intriguing bright wisp (near the center) measuring tens of miles across that may be a discreet, low-lying cloud in Pluto’s atmosphere; if so, it would be the only one yet identified in New Horizons imagery,” the statement reads. “This cloud – if that’s what it is – is visible for the same reason the haze layers are so bright: illumination from the sunlight grazing Pluto’s surface at a low angle. Atmospheric models suggest that methane clouds can occasionally form in Pluto’s atmosphere. The scene in this inset is 140 miles (230 kilometers) across.

“The inset at bottom right shows more detail on the night side of Pluto,” it continues. “This terrain can be seen because it is illuminated from behind by hazes that silhouette the limb. The topography here appears quite rugged, and broad valleys and sharp peaks with relief totaling 3 miles (5 kilometers) are apparent. This image, made from closer range, is much better than the lower-resolution images of this same terrain taken several days before closest approach. These silhouetted terrains therefore act as a useful ‘anchor point,’ giving New Horizons scientists a rare, detailed glimpse at the lay of the land in this mysterious part of Pluto seen at high resolution only in twilight. The scene in this inset is 460 miles (750 kilometers) wide.”