Scientists spotted an unusual geological feature on Pluto’s icy terrain that looks like a spider. This “icy spider” is actually a series of long fractures on the surface, all of which extends from a central point, forming like the shape of a spider.

“Oh, what a tangled web Pluto’s geology weaves,” says Oliver White in a statement. White is a member of the NASA Ames Research Centre’s New Horizons geology team in Moffett Field, California. “The pattern these fractures form is like nothing else we’ve seen in the outer solar system, and shows once again that anywhere we look on Pluto, we see something different.”

The images were taken on July 14, 2015 by the NASA spacecraft New Horizons’ Ralph/Multispectral Visible Imaging Camera (MVIC), 33,900 kilometres above Pluto. The scientists discovered that the longest of these six extensional fractures are aligned north-south.


Pluto’s unusual spider-like feature consists of at least six extensional fractures that converge to a point. Individual fractures can reach hundreds of miles long and appear to expose a reddish subsurface layer. Credits: NASA/JHUAPL/SwRI

Apparently, the longest extensional fracture is called Sleipnir Fossa, which measures more than 580 kilometres long. On the other hand, the shorter one aligns east-west and only measures up to100 kilometres long.

According to the scientists, the fractures intercept and spread out to the Tartarus Dorsa, a bladed terrain on Pluto.  Moreover, these legs show red deposits below the dwarf planet’s surface.


Location of the spider-like feature at the eastern edge of Pluto’s encounter hemisphere, as captured by NASA’s New Horizons spacecraft on July 14, 2015. Credits: NASA/JHUAPL/SwRI

Scientists from New Horizons believe that the fractures on the dwarf planet are due to the global-scale extension of the water-ice crust. The pattern of fractures that look like spider legs is most likely caused by a concentrated stress point in the crust under the area where the fractures meet.

It turns out that the icy spider looks like the fractured centres, also called novae, observed on Venus as well as the radial set of troughs, also known as the Pantheon Fossae formation, found on Mercury. The images from both planets are taken by NASA’s Magellan spacecraft and MESSENGER, respectively.