New Pluto Images Show Possible Dunes, Crepuscular Rays, Unimaginable Complexity

New Horizons scientists say they are “reeling” from the new images sent back from the spacecraft which were released today. The new data set shows an amazing range of complex features on Pluto’s surface and in its atmosphere.

New images show there might even be a field of dark wind-blown dunes, among other possibilities.

“Seeing dunes on Pluto — if that is what they are — would be completely wild, because Pluto’s atmosphere today is so thin,” said William B. McKinnon, a GGI deputy lead from Washington University, St. Louis. “Either Pluto had a thicker atmosphere in the past, or some process we haven’t figured out is at work. It’s a head-scratcher.”

Plus, a new view of Pluto’s hazy backlit atmosphere shows what are likely crepuscular rays — shadows cast on the haze by topography such as mountain ranges on Pluto, similar to the rays sometimes seen in the sky after the sun sets behind mountains on Earth.

Two different versions of an image of Pluto's haze layers, taken by New Horizons as it looked back at Pluto's dark side nearly 16 hours after close approach, from a distance of 480,000 miles (770,000 kilometers). The left version has had only minor processing, while the right version has been specially processed to reveal a large number of discrete haze layers in the atmosphere, and and subtle parallel streaks in the haze may be crepuscular rays- shadows cast on the haze by topography such as mountain ranges on Pluto, similar to the rays sometimes seen in the sky after the sun sets behind mountains on Earth. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.
Two different versions of an image of Pluto’s haze layers, taken by New Horizons as it looked back at Pluto’s dark side nearly 16 hours after close approach, from a distance of 480,000 miles (770,000 kilometers). The left version has had only minor processing, while the right version has been specially processed to reveal a large number of discrete haze layers in the atmosphere. Subtle parallel streaks in the haze may be crepuscular rays- shadows cast on the haze by topography such as mountain ranges on Pluto, similar to the rays sometimes seen in the sky after the sun sets behind mountains on Earth.Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.

Scientists say these new images reveal that Pluto’s global atmospheric haze has many more layers than scientists realized, and that the haze actually creates a twilight effect that softly illuminates nightside terrain near sunset, making them visible to the cameras aboard New Horizons.

“This bonus twilight view is a wonderful gift that Pluto has handed to us,” said John Spencer, a GGI deputy lead from SwRI. “Now we can study geology in terrain that we never expected to see.”

This image of Pluto from NASA's New Horizons spacecraft, processed in two different ways, shows how Pluto's bright, high-altitude atmospheric haze produces a twilight that softly illuminates the surface before sunrise and after sunset, allowing the sensitive cameras on New Horizons to see details in nighttime regions that would otherwise be invisible. The right-hand version of the image has been greatly brightened to bring out faint details of rugged haze-lit topography beyond Pluto’s terminator, which is the line separating day and night. The image was taken as New Horizons flew past Pluto on July 14, 2015, from a distance of 50,000 miles (80,000 kilometers). Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
This image of Pluto from NASA’s New Horizons spacecraft, processed in two different ways, shows how Pluto’s bright, high-altitude atmospheric haze produces a twilight that softly illuminates the surface before sunrise and after sunset, allowing the sensitive cameras on New Horizons to see details in nighttime regions that would otherwise be invisible. The right-hand version of the image has been greatly brightened to bring out faint details of rugged haze-lit topography beyond Pluto’s terminator, which is the line separating day and night. The image was taken as New Horizons flew past Pluto on July 14, 2015, from a distance of 50,000 miles (80,000 kilometers). Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

These new images are the first to be sent from the spacecraft since shortly after it flew past the Pluto system in July of this year. This is the beginning of an “intensive” downlink session that will last for a year or more, sending back the 50 gigabits or so of data the spacecraft collected and stored on its digital recorders during the flyby. These new images are “selected high priority” data-sets that the science team has been anxiously waiting for.

The new images are “lossless” — meaning the data sent back from the New Horizon spacecraft is using a type of data compression algorithms that allows the original data to be perfectly reconstructed from the compressed data. Planetary astronomer Alex Parker said on Twitter that this means the even views we’ve seen in the previous Pluto images from New Horizons are much sharper and crisper.

Here are more:

A close-up of a dark area  on the edge of the heart-shaped light region on Pluto. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
A close-up of a dark area on the edge of the heart-shaped light region on Pluto. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

Besides the dunes and new atmospheric imagery, other views show nitrogen ice flows that apparently oozed out of mountainous regions onto plains, and even networks of valleys that may have been carved by material flowing over Pluto’s surface. They also show large regions that display chaotically jumbled mountains, which reminded many of the terrain on Jupiter’s icy moon Europa.

“The surface of Pluto is every bit as complex as that of Mars,” said Jeff Moore, leader of the New Horizons Geology, Geophysics and Imaging (GGI) team at NASA’s Ames Research Center. “The randomly jumbled mountains might be huge blocks of hard water ice floating within a vast, denser, softer deposit of frozen nitrogen within the region informally named Sputnik Planum.”

In the center of this 300-mile (470-kilometer) wide image of Pluto from NASA’s New Horizons spacecraft is a large region of jumbled, broken terrain on the northwestern edge of the vast, icy plain informally called Sputnik Planum, to the right. The smallest visible features are 0.5 miles (0.8 kilometers) in size. This image was taken as New Horizons flew past Pluto on July 14, 2015, from a distance of 50,000 miles (80,000 kilometers). Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
In the center of this 300-mile (470-kilometer) wide image of Pluto from NASA’s New Horizons spacecraft is a large region of jumbled, broken terrain on the northwestern edge of the vast, icy plain informally called Sputnik Planum, to the right. The smallest visible features are 0.5 miles (0.8 kilometers) in size. This image was taken as New Horizons flew past Pluto on July 14, 2015, from a distance of 50,000 miles (80,000 kilometers). Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

There’s even a sharper view of Charon, which we discussed in an article earlier today, with its mysterious red feature on the north pole.

This image of Pluto's largest moon Charon, taken by NASA's New Horizons spacecraft 10 hours before its closest approach to Pluto on July 14, 2015 from a distance of 290,000 miles (470,000 kilometers), is a recently downlinked, much higher quality version of a Charon image released on July 15. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.
This image of Pluto’s largest moon Charon, taken by NASA’s New Horizons spacecraft 10 hours before its closest approach to Pluto on July 14, 2015 from a distance of 290,000 miles (470,000 kilometers), is a recently downlinked, much higher quality version of a Charon image released on July 15. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.

The New Horizons spacecraft is now about 5 billion kilometers (more than 3 billion miles) from Earth, and more than 69 million kilometers (43 million miles) beyond Pluto. The team says the spacecraft is healthy and all systems are operating normally.

You can see all the latest imagery sent back from New Horizons at this website. New images will be added every week, according to the New Horizons staff, likely on Fridays.

Additional reading: NASA press release.

15 Replies to “New Pluto Images Show Possible Dunes, Crepuscular Rays, Unimaginable Complexity”

  1. Umm… wow. Where is the heat coming from to re-surface like that? Tidal acceleration? They are as tidally locked as you can get, so there must have been some friction at one time. Energy is transferred and heat created. I imagine once all the orbits and rotations are in sync there is no more torque?

    1. Good point. Once they’re tidally locked, there’s no remaining energy to dissipate, so they may as well be solitary objects.

      So if the evidence shows a geologically-young surface, with low crater counts, then we have two choices:
      1) Retain the falsified (Grand Tack) model and append secondary ad hoc mechanisms to explain away the discrepancies, or
      2) Believe the evidence in favor of a young Pluto (and young Ceres with its low crater count) and create a new primary predictive ideology.

      1. You got it backwards: twisting the evidence to fit the theory by tacking on secondary ad hoc mechanisms is the height of pseudoscience practiced by academia.

      2. Low crater count. On Ceres. What? Ceres’s surface is saturated with craters, meaning there’s no part of its surface you could drop a meteorite without hitting a pre-existing crater. It has literally as many craters as could possibly fit on it.

      3. The link is for Ceres, but I should have prefaced the abrupt leap to the inner solar system.

        I suggest that Ceres, (possibly Hyperion), and the cold classical Kuiper belt objects (including some or many of the Plutinos) condensed by gravitational instability (GI) from a secondary debris disk from the ashes of the binary spiral-in merger of our former binary brown-dwarf Companion to the Sun at 542 Ma. (And the asymmetrical merger explosion gave the Companion escape velocity from the Sun.)

        Not only does this constitute a primary PREDICTIVE ideology for geologically young Pluto and low crater count of Ceres, but it unifies a number of formerly disparate solar system phenomena:

        Alternative solar system ideology in the context of a former quadruple-star solar system:
        – Triple fragmentation of an original protostar with excess angular momentum forms a hierarchical wide binary star system composed of two close binary pairs: binary-Sun and binary-Companion
        – Uranus and Neptune condense planetesimals from a circumbinary protoplanetary disk by gravitational instability (GI) against the binary resonances, forming Uranus and Neptune by [‘hybrid accretion’ (Thayne Currie 2005)] And the leftover planetesimals, scattered disk objects (SDOs), are scattered to the scattered disc
        – Binary-Sun components isolate outer protostar layers with excess angular momentum during the runaway gravitational collapse forming the second hydrostatic core (SHSC), promoted by nearly-isothermal gravitational collapse mediated by endothermic hydrogen dissociation. The isolated outer layers themselves undergo GI to form the hot-Jupiter proto-planets, Saturn and Jupiter around the two binary-Sun components.
        – Dynamic evolution of the quad system causes binary-Sun to spiral in, leaving Jupiter and Saturn behind in circumbinary orbits, and the stellar components merge at 4,568 Ma, creating a primary debris disk, along with stellar-merger nucleosynthesis r-process radionuclides, principally 26Al and 60Fe and enriching the Sun and primary debris disk in the helium-burning stable isotopes, principally 12C and 16O.
        – Asteroids condense by GI against the Sun’s magnetic corotation radius, forming Mercury by hybrid accretion. Chondrites condense in situ against Jupiter’s strongest inner resonances. (Hot classical) Kuiper belt objects (KBOs) condense against Neptune’s strongest outer resonances, principally the 3:2 and 1:2 resonances.
        – Continued dynamic evolution of the triple star system causes the components of binary-Companion to spiral in, increasing the wide-binary Sun-Companion period at an exponential rate over the next 4 billion years.
        – As the solar system barycenter (SSB) between Sun and Companion moves out from the Sun (by Galilean relativity) at an exponential rate over time, it perturbs first Plutinos at 4.22 Ga followed by the cubewanos from 4.1 to 3.8 Ga, causing a double pulse late heavy bombardment of KBOs in the inner solar system.
        – The binary brown-dwarf components of former binary-Companion merge at 542 Ma in an asymmetrical merger explosion that gives the Companion escape velocity from the Sun, but the fossil major-axis alignment of detached objects like Sedna and 2012 VP113 are still visible, although KBOs and SDOs in shorter-period orbits have largely randomized by now. The loss of the former centrifugal force of the Sun around the SSB caused heliocentric objects into lower orbits, including Venus (in a former synchronous orbit around the Sun) resulting in its slight retrograde rotation. Earth’s orbital upheaval is recorded in the Great Unconformity.
        – A 542 Ma secondary debris disk formed from the binary-merger ashes, condensed cold classical KBOs (many of which fragmented to form binaries due to excess angular momentum) including binary Pluto (explaining its geologically-young surface) and Ceres with its low crater count.

    2. The heat sources are small, but it’s enough with the properties of nitrogen ice. It is a very poor heat conductor, and it turns into vapor easily. If the radionuclide mixing ratio in Pluto’s core is similar to that of Earth, heat flow from radioactive decay would be 3-4 milliwatts per square meter. N2 Ice conducts 0,2 W/(m*K), and the bottom of Sputnik glacier could not be warmer than melting point, 63K (liquid N2 has a lower density than N2 ice, and it would immediately rise to the surface). The surface is 30-40K, so a few km thick layer of ice would be enough to start viscous convection, like in Earth’s mantle. Maube these polygonal features are the convective cells! And this would quickly erase craters from glacier’s surface.
      And since the heat of evaporation is ~200000 J/kg, any significant impact on glacier would result in temporary atmosphere, much more dense than at the equilibrium conditions. A 50 km Kuiper Belt object would even be enough to rise T and p past the triple point. The resulting rains and snow and wind would leave traces all over the surface, like flow channels, glacial valleys on mountain slopes, and later, dunes and wind erosion features. (possibly no much larger impacts in Pluto’s history, or the erosion would be much more widespread than observed now)

      1. Good point. When I submitted my comment about the terrain I hadn’t seen your reply, but most of us forget how different nitrogen ice and water ice would be at these temperatures.

  2. You don’t need tidal heating in every case. Nitrogen can be liquified by solar energy at the temperatures found on Pluto. So the images above (4th and 5th one down) seem to show a “sea” of liquid nitrogen capped with ice that is undermining the crater/basin wall. In the fourth image down there is what looks like a dark debris flow from the wall on the lower side of the image and towards the hummocky terrain. In the 5th image there is a clear margin of hummocky terrain along the entire edge of the flat basin adjoining the wall, suggesting this is undermined terrain. It could be water ice that has slumped off after being undermined by liquid nitrogen from the basin. You see the same features on Earth where rock is undermined by water. More extreme cases such as Mt St Helens, where there was a massive collapse leave the classic hummocky terrain behind; while less extreme show the rippling effect in the dark material that is seen in image 4.

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