New Horizons image shows where huge nitrogen ice blobs merged on Pluto's surface

The newest image of Pluto's ice fields offers a fascinatingglimpse of what researchers believe isthe movement of huge, solid nitrogen ice blobson the surface of the distant dwarf planet.

Received by scientists from NASA's New Horizons spacecrafton Christmas Eve, the composite photo depicts part of the expansive icy plain that makes up the left side of Pluto's famous heart-shaped region. Sometimes called the Sputnik Planum, the plain consistsof massive ice "blobs"made up of solid but mobile nitrogen icethat appear on Pluto's surface as amorphous shapes that rub against one another.

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NASA scientists theorize that the blobs are a product of the convection of a kilometres-deep layer of nitrogenice thatrises and falls as it is heated from below by the dwarf planet's modest internal temperature.WilliamMcKinnon, deputy lead of NASA'sNew Horizons geology team, said in a news release that"this part of Pluto is acting like a lava lamp, if you can imagine a lava lampas wide as, and even deeper than, the Hudson Bay."

Computer models show that over timethe blobs change shape and even merge with neighbouring formationsand that's where the newest image gets interesting.

In the bottom left corner of the composite photo, an "X" formationmarks where four of the blobs likelymet and eventually merged into one another, reinforcing prevailing theories about the nature of geologic activity in this region of Pluto.

You can explore the entire image, which captures an expanse 80 kilometres wide and 700 kilometres long and shows several other interesting surface features, here.

NASA also released an image of Pluto's so-called Viking Terra area this week.

The composite photo was created using images taken from two different cameras on board New Horizons andshows high concentrations of deep red tholins aerosol particles that form throughreactions in Pluto's atmosphere involving methane and nitrogen in the bases of craters andin channels.

In thick deposits, tholins are generally considered immobile and it remains unclear how the particles are migrating to certain areas.

Researchers think the particles are being carried along by subsurfaceice flows or blown around by Pluto's considerable winds, eventually settling in low lying regions.

Check out a larger version of the composite image here.