Category Archives: Pluto

“Houston, We Have Geology”

Pluto Lives!

The latest image from Pluto is showing distinct features on the planet's surface. NASA-JHUAPL-SWRI
The latest image from Pluto is showing distinct features on the planet’s surface. NASA-JHUAPL-SWRI
An annotated version of the Pluto image at left.  NASA. The reference globe shows that we are looking roughly at Pluto's north pole at the top left, and the dark regions are along the equator. NASA-JHUAPL-SWRI
An annotated version of the Pluto image above.
NASA. The reference globe shows that we are looking roughly at Pluto’s north pole at the top left, and the dark regions are along the equator. NASA-JHUAPL-SWRI

The world is waking up to a vision of Pluto that now tells us this planet is a dynamic place — not a frozen desert, but a world with landscapes that are still just enough out of focus that it’s tough to tell exactly what they are. According to Alan Stern, the features in this image are indicative of something quite exciting. There appear to be complex surface structures pictured in this new image sent back by New Horizons just yesterday. “In this new image are what appear to be polygonal features, a complex band of terrain stretching east-northeast across the planet, approximately 1,000 miles long; and a complex region where bright terrains meet the dark terrains of the whale,” he said. “After nine and a half years in flight, Pluto is well worth the wait.”

The shapes we’re seeing on Pluto indicate some kind of geological activity, although the details are (forgive me) still a bit fuzzy. There are a number of things that can make these shapes you see on the icy surface. Think about what it looks like as ice and snow melt (sublimate) here on Earth. If you have a dirty snowbank, for example, the snow can melt preferentially, leaving strange shapes behind. On Pluto, there are mixtures of ice on the surface, and they all react a little differently to solar heating and UV light. Also, if you have a heated bit of ground on Earth, snow melts preferentially over that (and also refreezes when temperatures drop).

I honestly don’t know what’s doing the shaping of Pluto’s surface, but it’s a dynamic process (meaning it’s happening in real time). If that truly bears out, and we should know more soon, then Pluto is very  much a “living” world, perhaps in much the same way that Triton at Neptune continues to spew geysers from beneath its surface, or Enceladus at Saturn does the same thing. The big questions now are: what’s causing these surface features, and what’s causing that process? Stay tuned!

Your Daily Moment of Pluto Zen

The View Improving, Less than One Pluto Day from Encounter

Pluto (right) and Charon (left) in a LORRI image, colorized with color information from the RALPH instrument onboard New Horizons. Courtesy NASA-JHUAPL-SWRI
Pluto (right) and Charon (left) in a LORRI image, colorized with color information from the RALPH instrument onboard New Horizons. Courtesy NASA-JHUAPL-SWRI

Next week, we’ll be seeing some pretty sharp views of Pluto and Charon, but for my money, the view’s starting to get pretty good now!  Here’s the latest image from July 8, when New Horizons was 6 million kilometers (3.7 million miles) from the pair and closing in fast. Now we can start to see more details, including what looks like surface features that could be impact craters. If so, and bear in mind that the craters aren’t yet proven to be craters, then the Geology, Geophysics, and Imaging team members will be looking at those holes in the Pluto surface to see what’s hidden below. One thing about impact craters, when they are created, their formation reveals the layers of ground (or other materials) below the surface. So, this will be an important discovery if New Horizons can “peek” down beneath the icy crust.

Personalities at the Frontier of the Solar System

What’s really cool about this image? It’s showing us Pluto has its own personality, just as Charon does, and they’re both worlds in their own rights. Pluto is covered with a mixture of nitrogen, carbon monoxide and methane ices, and their colors are made as solar ultraviolet radiation darkens the organic-rich ices.  Charon is more uniformly darkish gray, with a mixture of water and ammonia compounds.  How did they get this way? How have Pluto and Charon stayed together for billions of years? What else will we find?

Stay tuned!