Tag Archives: New Horizons

New Horizons looks back at Pluto

One year after New Horizons’ breath-taking fly-by of Pluto, the science team has written a review of what they have learned.

They list what they consider the mission’s top ten discoveries, which I think can be summed up in one phrase: the uncertainty of science. Pluto was more active geologically and atmospherically than predicted by all models. It was also more complex. Other surprises: Both Pluto and Charon show evidence of sub-surface liquid oceans of water. Charon’s dark red polar baffles them. They unexpectedly found no additional moons, and also discovered that as far as they can tell by the available data, the moons were all formed when Pluto formed, something they also did not expect.

The one thing that I expected that did happen? We got close, and discovered things we had not expected. Be prepared for further surprises when New Horizons flies past Kuiper Belt object 2014 MU69 on January 1, 2019.

NASA okays New Horizons mission extension, rejects Dawn asteroid fly-by

NASA has approved an extension of the New Horizons mission to fly past Kuiper Belt object 2014 MU69 on January 1, 2019.

In the same press release the agency announced that they have decided that they will get more worthwhile science by keeping Dawn in orbit around Ceres for the reminder of its life, rather then sending it on a proposed fly by of another asteroid.

Pluto might have subsurface liquid water ocean

An analysis of the data sent back from New Horizons strongly suggests that Pluto might still have a liquid ocean of water beneath its surface.

The pictures New Horizons sent back from its close encounter with the Kuiper Belt’s most famous denizen showed that Pluto was much more than a simple snowball in space. It has an exotic surface made from different types of ices — water, nitrogen and methane. It has mountains hundreds of meters high and a vast heart-shaped plain. It also has giant tectonic features — sinuous faults hundreds of kilometers long as deep as 4 kilometers. It was those tectonic features that got scientists thinking that a subsurface ocean was a real possibility for Pluto. “What New Horizons showed was that there are extensional tectonic features, which indicate that Pluto underwent a period of global expansion,” Hammond said. “A subsurface ocean that was slowly freezing over would cause this kind of expansion.”

Scientists think that there may have been enough heat-producing radioactive elements within Pluto’s rocky core to melt part of the planet’s ice shell. Over time in the frigid Kuiper belt, that melted portion would eventually start to refreeze. Ice is less dense than water, so when it freezes, it expands. If Pluto had on ocean that was frozen or in the process of freezing, extensional tectonics on the surface would result, and that’s what New Horizons saw.

I must emphasize that this result has a great deal of uncertainty. Nonetheless, it suggests once again that we might liquid water in space in a lot of places we never expected or imagined.

Pluto’s jagged shores

Pluto's jagged shoreline

Cool image time! The picture on the right, taken by New Horizons during its July 2015 flyby and cropped and reduced here, shows the reddish hues of the Krun Macula dark region along the shore of Pluto’s vast nitrogen ice plains. The hillsides here rise about a mile and a half above both the plains and the valleys, making them deeper than the Grand Canyon. The hills are “believed to get its dark red color from tholins, complex molecules found across Pluto.”

Pluto: the world’s largest lava lamp

In comparing the New Horizons’ data with computer simulations, scientists have determined that the frozen nitrogen in the heart-shaped Sputnik Planum region rises and sinks as the nitrogen is heated from below.

McKinnon and colleagues believe the pattern of these cells stems from the slow thermal convection of the nitrogen-dominated ices that fill Sputnik Planum. A reservoir that’s likely several miles deep in some places, the solid nitrogen is warmed by Pluto’s modest internal heat, becomes buoyant and rises up in great blobs – like a lava lamp – before cooling off and sinking again to renew the cycle. The computer models show that ice need only be a few miles deep for this process to occur, and that the convection cells are very broad. The models also show that these blobs of overturning solid nitrogen can slowly evolve and merge over millions of years. Ridges that mark where cooled nitrogen ice sinks back down can be pinched off and abandoned, resulting in Y- or X-shaped features in junctions where three or four convection cells once met.

New Horizons’ best Pluto close-up

Pitted nitrogen ice plains on Pluto

The New Horizons science team has released the highest resolution image across Pluto’s face, taken by the spacecraft during its flyby last year.

This mosaic strip, extending across the hemisphere that faced the New Horizons spacecraft as it flew past Pluto on July 14, 2015, now includes all of the highest-resolution images taken by the NASA probe. With a resolution of about 260 feet (80 meters) per pixel, the mosaic affords New Horizons scientists and the public the best opportunity to examine the fine details of the various types of terrain the mosaic covers, and determine the processes that formed and shaped them.

The view extends from the “limb” of Pluto at the top of the strip, almost to the “terminator” (or day/night line) in the southeast of the encounter hemisphere, seen at the bottom of the strip. The width of the strip ranges from more than 55 miles (90 kilometers) at its northern end to about 45 miles (75 kilometers) at its southern end. The perspective changes greatly along the strip: at its northern end, the view looks out horizontally across the surface, while at its southern end, the view looks straight down onto the surface.

Go to the full image, go to its top, center your browser on the image, and then pan down slowly to see it in all its glory. The image above is cropped from about two-thirds of the way down, about when the terrain is transitioning from what they call cellular nitrogen ice plains to pitted non-cellular nitrogen ice plains. It includes what looks like a cluster of cave pits on the left.

They have also provided a video which does the same as panning down yourself, but adds a scale and labeling.

Pluto’s solar wind interaction more like a planet’s

Data from New Horizons has found that Pluto, in its interaction with the solar wind, behaves more like a planet than a comet.

Previously, most researchers thought that Pluto was characterized more like a comet, which has a large region of gentle slowing of the solar wind, as opposed to the abrupt diversion solar wind encounters at a planet like Mars or Venus. Instead, like a car that’s part gas- and part battery-powered, Pluto is a hybrid, the researchers say. “This is an intermediate interaction, a completely new type. It’s not comet-like, and it’s not planet-like. It’s in-between,” McComas said. “We’ve now visited all nine of the classical planets and examined all their solar wind interactions, and we’ve never seen anything like this.”

…Pluto continues to confound. Since it’s so far from the sun – an average of about 5.9 billion kilometers (3.7 billion miles) – and because it’s so small, scientists thought Pluto’s gravity would not be strong enough to hold heavy ions in its extended atmosphere. But, “Pluto’s gravity clearly is enough to keep material sufficiently confined,” McComas said. Further, the scientists found that very little of Pluto’s atmosphere is comprised of neutral particles converted to electrically charged ions and swept out into space.

As I’ve written previously, we simply don’t know enough yet about planets to come up with a reasonable definition. As far as I’m concerned, Pluto will remain a planet until we do.

The depressed heart of Pluto

Using elevation data gathered by New Horizons during its fly-by of Pluto last year scientists have created an elevation map of the heart-shaped Sputnik Planum that shows that its central region is on average two miles deeper than the surrounding terrain.

The data even shows giant blocks of frozen water floating on the denser nitrogen ice.

Halo craters on Pluto

More images from New Horizons reveal even more strange terrain on Pluto.

Data suggest that the bright rims are made of methane ice, while the dark crater floors are made of water ice, though why this has happened is a complete mystery. As they note at the link above, “Exactly why the bright methane ice settles on these crater rims and walls is a mystery; also puzzling is why this same effect doesn’t occur broadly across Pluto.”

Frozen pond on Pluto

Cool image time! The New Horizons’ science team on Thursday released a new image, showing a remarkable frozen pond on Pluto. As they note:

“In addition to this possible former lake, we also see evidence of channels that may also have carried liquids in Pluto’s past,” said Alan Stern, Southwest Research Institute, Boulder, Colorado—principal investigator of New Horizons and lead author of a scientific paper on the topic submitted to the journal Icarus.

This feature appears to be a frozen, former lake of liquid nitrogen, located in a mountain range just north of Pluto’s informally named Sputnik Planum. Captured by the New Horizons’ Long Range Reconnaissance Imager (LORRI) as the spacecraft flew past Pluto on July 14, 2015, the image shows details as small as about 430 feet (130 meters). At its widest point the possible lake appears to be about 20 miles (30 kilometers) across.

I have not posted the image here, because I have already posted this image on Behind the Black, back on October 6, 2015, in which I wrote in part,

The image shows what looks like an enclosed lake of some material, probably nitrogen, with the bedrock entrapping it solid ice. In addition, as you move away from the shore and head uphill it looks like you travel across several geological layers made of different materials. Figuring out how they formed in this way could probably keep a geologist busy for his or her entire life.

I had also then noted how I expected the scientists would be “drooling” over this image, and that I expected a full press release on it at some point. It took six months, but here we are.

New Horizons’ future research goals

On Monday at a planetary science conference Alan Stern, the project scientist for New Horizons, outlined the science goals in studying the Kuiper Belt should the spacecraft’s mission be extened through 2021.

The main goal will be the January 1, 2019 fly-by of Kuiper Belt object 2014 MU69, estimated to be between 12 to 24 miles across. However, the proposal also includes the following:

“In addition to making a close flyby of MU69, we’re also going to be close enough in range to study quite a number of other small KBOs, and some large ones that are on the Pluto scale,” Stern said. New Horizons will be able to study them in ways that could never be accomplished from Earth. The closeness of the spacecraft will enable high resolution observations, and the ability to look for satellites that cannot be seen from Earth observatories or with the Hubble Telescope.

“Because we are looking back on the rest of the solar system, at the Kuiper Belt and the Centaur Population,” Stern said, “we’re going to be able to study another 18 or 20 small bodies to determine whether or not the recently discovered rings around the centaur Chariklo are a common occurrence, or something anomalous. And I don’t know of any other way over the next several years, except through New Horizons, that we can develop a data set like that.”

What I find amazing is that it appears from Stern’s remarks that NASA has not yet approved this proposal. Before the team discovered 2014 MU69, I would have been more skeptical about extending the mission, but since they will be able to do a close fly-by of a type of object never before seen, and considering the time and cost it takes to get to the Kuiper Belt, it seems foolish now to not approve this mission extension.

Pluto 8 months after fly-by

The New Horizons science team today published five papers summarizing what they have so far learned from the data obtained during last year’s July 14 fly-by and since downloaded.

Two of the many discoveries are to me the most interesting: The first illustrates Pluto’s strange and very active geology:

Age-dating of Pluto’s surface through crater counts has revealed that Pluto has been geologically active throughout the past 4 billion years. Further, the surface of Pluto’s informally named Sputnik Planum, a massive ice plain larger than Texas, is devoid of any detectable craters and estimated to be geologically young – no more than 10 million years old.

Moreover, the materials that cause Pluto to be geologically active are much more complicated than anything on Earth:

Scientists studying Pluto’s composition say the diversity of the planet’s landscape stems from eons of interaction between highly volatile and mobile methane, nitrogen and carbon monoxide ices with inert and sturdy water ice. “We see variations in the distribution of Pluto’s volatile ices that point to fascinating cycles of evaporation and condensation,” said Will Grundy, from Lowell Observatory in Flagstaff, Arizona, and lead author of the composition paper. “These cycles are a lot richer than on Earth, where there’s really only one material that condenses and evaporates – water. On Pluto, there are least three materials, and while they interact in ways we don’t yet fully understand, we definitely see their effects all across Pluto’s surface.”

The second discovery that fascinates me has to do with the formation of Pluto and all its moons:

The high albedos (reflectiveness) of Pluto’s small satellites are entirely different from the much lower albedos of the small bodies in the general Kuiper Belt population (which range from about 5 to 20 percent). This difference lends further support to the idea that these satellites were not captured from the general Kuiper Belt population, but instead formed by agglomeration in a disk of material produced in the aftermath of the giant collision that created the entire Pluto satellite system.

In other words, Pluto and its moons are not a collection of different Kuiper Belt objects brought together over time. Instead, they formed together.

Clouds on Pluto?

A report from New Scientist today claims that the New Horizons science team has possibly seen individual clouds in some images.

Grundy had spotted features in the haze on the edge – or “limb” – of Pluto that seemed to stand out from the distinct layers. But more intriguingly, he had also seen a bright feature crossing different parts of the landscape, suggesting it was hovering above. The email kicked off a discussion as to whether the clouds were real, because it was difficult to see whether they cast shadows on the ground. The team also deliberated over the exact distinction between clouds and hazes. “One way to think of it is that clouds are discrete features, hazes widespread,” wrote Alan Stern, who heads up the New Horizons mission.

There has been no public mention of the clouds, suggesting that the team isn’t sure about the detection.

Methane ice on Pluto’s mountain peaks

New images from New Horizons of the dark Cthulhu region have revealed white-capped mountain peaks, thought to be methane ice.

Scientists think this bright material could be predominantly methane that has condensed as ice onto the peaks from Pluto’s atmosphere. “That this material coats only the upper slopes of the peaks suggests methane ice may act like water in Earth’s atmosphere, condensing as frost at high altitude,” said John Stansberry, a New Horizons science team member from Space Telescope Science Institute, Baltimore, Maryland.

We as humans are attracted to features on other worlds that remind us of Earth, mainly because this allows us to quickly understand what we are seeing. It is important however to remind ourselves continually that Pluto is not Earth, and is in fact a very alien place. Many things we think we recognize are really very different than what we assume. For example, the methane ice here is coating mountains made of water ice that is as stable as granite in Pluto’s super cold environment.

One more thing: It appears that at this point, seven months after New Horizons flew past Pluto, they have still only downloaded less than half the data obtained. This is not a problem, as this is how things were planned, but it does mean that there are likely many more discoveries yet for us to see.

A frozen underground ocean on Charon?

Data from New Horizons of the surface of Pluto’s moon Charon now suggests that the satellite once had an underground ocean that is now frozen.

Charon’s outer layer is primarily water ice. When the moon was young this layer was warmed by the decay of radioactive elements, as well as Charon’s own internal heat of formation. Scientists say Charon could have been warm enough to cause the water ice to melt deep down, creating a subsurface ocean. But as Charon cooled over time, this ocean would have frozen and expanded (as happens when water freezes), pushing the surface outward and producing the massive chasms we see today.

The first geology map of Pluto

Geology map of Pluto

The New Horizons science team has now released the first geology map of a portion of Pluto, seen by the spacecraft during its fly-by last year.

It is definitely worth your while to take a look at the full image, along with the legend explaining the different surface features. Most of the geological terms are merely descriptive, but the careful breakdown still provides a much deeper understanding of what is there.

The floating mountains of Pluto

Pluto's floating mountains

The New Horizons science team has released a new image of Pluto’s smooth heart-shaped area, dubbed Sputnik Planum, focusing this time on the mountains of water ice that pop up through the plain and are apparently floating on the nitrogen sea, having broken off from the shoreline.

Because water ice is less dense than nitrogen-dominated ice, scientists believe these water ice hills are floating in a sea of frozen nitrogen and move over time like icebergs in Earth’s Arctic Ocean. The hills are likely fragments of the rugged uplands that have broken away and are being carried by the nitrogen glaciers into Sputnik Planum. ‘Chains’ of the drifting hills are formed along the flow paths of the glaciers. When the hills enter the cellular terrain of central Sputnik Planum, they become subject to the convective motions of the nitrogen ice, and are pushed to the edges of the cells, where the hills cluster in groups reaching up to 12 miles (20 kilometers) across.

I have significantly cropped the image to show it here. Be sure and check out the full version, because there is a wealth of fascinating details in it.

Water ice on Pluto’s surface

The uncertainty of science: An analysis of data from New Horizons suggests that water ice is more widespread on Pluto’s surface than previously believed.

The new map shows exposed water ice to be considerably more widespread across Pluto’s surface than was previously known — an important discovery. But despite its much greater sensitivity, the map still shows little or no water ice in the informally named places called Sputnik Planum (the left or western region of Pluto’s “heart”) and Lowell Regio (far north on the encounter hemisphere). This indicates that at least in these regions, Pluto’s icy bedrock is well hidden beneath a thick blanket of other ices such as methane, nitrogen and carbon monoxide.

As the press release notes, water ice is actually “Pluto’s crustal ‘bedrock'”, so there really is plenty there. It is just buried below a surface of methane, nitrogen, and carbon monoxide “topsoil”.

New spectacular images of Pluto

Pluto's mountainous shoreline

Many cool images! The New Horizons science team has today released new images from the spacecraft’s close fly-by of Pluto.

These latest pictures are part of a sequence taken near New Horizons’ closest approach to Pluto, with resolutions of about 250-280 feet (77-85 meters) per pixel – revealing features less than half the size of a city block on the diverse surface of the distant planet. In these new images, New Horizons captured a wide variety of spectacular, cratered, mountainous and glacial terrains.

I have cropped and lowered the resolution of the image above to fit it here. Make sure you click on the link to see it and the other images. As they note,

In this highest-resolution image from NASA’s New Horizons spacecraft, great blocks of Pluto’s water-ice crust appear jammed together in the informally named al-Idrisi mountains. Some mountain sides appear coated in dark material, while other sides are bright. Several sheer faces appear to show crustal layering, perhaps related to the layers seen in some of Pluto’s crater walls. Other materials appear crushed between the mountains, as if these great blocks of water ice, some standing as much as 1.5 miles high, were jostled back and forth. The mountains end abruptly at the shoreline of the informally named Sputnik Planum, where the soft, nitrogen-rich ices of the plain form a nearly level surface, broken only by the fine trace work of striking, cellular boundaries and the textured surface of the plain’s ices (which is possibly related to sunlight-driven ice sublimation).

Today’s release also includes a short animation of a faint distant Kuiper Belt object, assembled by four images taken by New Horizons. The images don’t show much more than a streak of light, but the feat of imaging this object by a spacecraft billions of miles away in this manner is breath-taking.

Ice volcanoes, spinning moons, and more proof of geologic activity

The New Horizons science team has released more results from the spacecraft’s July 14 fly-by, revealing the existence of what look like two giant ice volcanoes on Pluto, data that suggests the smaller moons spin like tops, and a census of Pluto’s craters that show them distributed very unevenly across the planet’s surface, suggesting that large parts of Pluto’s surface have been resurfaced and thus have been geologically active.

One discovery gleaned from the crater counts also challenges the most popular theory about the formation of objects in the Kuiper Belt.

Crater counts are giving the New Horizons team insight into the structure of the Kuiper Belt itself. The dearth of smaller craters across Pluto and its large moon Charon indicate that the Kuiper Belt likely had fewer smaller objects than some models had predicted. This leads New Horizons scientists to doubt a longstanding model that all Kuiper Belt objects formed by accumulating much smaller objects of less than a mile wide. The absence of small craters on Pluto and Charon support other models theorizing that Kuiper Belt objects tens of miles across may have formed directly, at their current—or close to current—size.

In fact, the evidence that many Kuiper Belt objects could have been “born large” has scientists excited that New Horizons’ next potential target – the 30-mile-wide (40-50 kilometer wide) KBO named 2014 MU69 – which may offer the first detailed look at just such a pristine, ancient building block of the solar system.

As always, the results here are significantly uncertain. They are giving us a glimpse into the geology of rocky planets far from stars, but only a glimpse. I guarantee that any theories formed from this data will be incomplete and will likely be proven wrong.

New Horizons on the way to 2014 MU69

On Wednesday New Horizons successfully completed the fourth and last engine burn to change its trajectory to rendezvous with Kuiper Belt object 2014 MU69 in January 2019.

These were the spacecraft’s longest and most complicated mid-course corrections. They were also achieved at a greater distance from Earth than any previous such maneuver.

Pluto’s meandering canyons

canyons of Pluto

Cool image time! In scrolling through the new raw images downloaded from New Horizons today I came across an image, one of several, that showed what clearly appeared to be meandering canyons carved by flowing liquid.

To show it here, I have cropped it and reduced its size somewhat, highlighting the most interesting features. As you can see, the largest canyon not only appears to have a dark floor, it cuts right through an older crater. Smaller canyons do the same thing. In addition, many of the craters seem to be ponded with the same dark material that floors the canyons, while some of the smaller canyons show tributaries that come together, just like rivers. Are these flows of liquid nitrogen?

I eagerly await the conclusions of the scientists, who are probably only slightly less baffled by these features as I am.

Be sure and check out the full image, as well as the other raw images. The data continue to come in from New Horizons, but the science team is no longer under the same kind of public pressure to make announcements or hold press conferences. There are gems hidden there that are worth looking at, even if they are not as yet accompanied by any scientific analysis.

Pluto in 3D

The New Horizons science team has released its first 3D image of the surface of Pluto.

You need red/blue stereo glasses to view it.

The image shows an ancient, heavily cratered region of Pluto, dotted with low hills and cut by deep fractures, which indicate extension of Pluto’s crust. Analysis of these stereo images shows that the steep fracture in the upper left of the image is about 1 mile (1.6 kilometers) deep, and the craters in the lower right part of the image are up to 1.3 miles (2.1 km) deep. Smallest visible details are about 0.4 miles (0.6 kilometers) across.

My impression of the image, using the glasses, makes me wonder if they have exaggerated the vertical depth so that it would stand out. The craters look more like pits than craters. And if they didn’t exaggerate the vertical depth, then that means that impacts on Pluto produce craters that are very different than those seen in the inner solar system.

Another Pluto Moon revealed


The uncertainty of science: The New Horizons science team has released their best image of Pluto’s moon Kerberos, finding it to be nothing like what they expected.

Before the New Horizons encounter with Pluto, researchers had used Hubble Space Telescope images to “weigh” Kerberos by measuring its gravitational influence on its neighboring moons. That influence was surprisingly strong, considering how faint Kerberos was. They theorized that Kerberos was relatively large and massive, appearing faint only because its surface was covered in dark material. But the small, bright-surfaced, Kerberos now revealed by these new images show that that idea was incorrect, for reasons that are not yet understood.

Instead, Kerberos is much smaller than expected, and its surface is bright, suggesting it is covered by relatively clean ice. It is also double lobed, kind of like Comet 67P/C-G.

Ice and blue skies on Pluto

New data downloaded from New Horizons has confirmed the presence of ice on the planet’s surface, as well as suggesting that the planet’s sky might actually be colored blue.

The haze particles themselves are likely gray or red, but the way they scatter blue light has gotten the attention of the New Horizons science team. “That striking blue tint tells us about the size and composition of the haze particles,” said science team researcher Carly Howett, also of SwRI. “A blue sky often results from scattering of sunlight by very small particles. On Earth, those particles are very tiny nitrogen molecules. On Pluto they appear to be larger — but still relatively small — soot-like particles we call tholins.”

Scientists believe the tholin particles form high in the atmosphere, where ultraviolet sunlight breaks apart and ionizes nitrogen and methane molecules and allows them to react with each other to form more and more complex negatively and positively charged ions. When they recombine, they form very complex macromolecules, a process first found to occur in the upper atmosphere of Saturn’s moon Titan. The more complex molecules continue to combine and grow until they become small particles; volatile gases condense and coat their surfaces with ice frost before they have time to fall through the atmosphere to the surface, where they add to Pluto’s red coloring.

Guess where?

Pluto lake

I found the image on the right while trolling about on the various raw image sites for NASA’s planetary missions. No press release yet, and maybe there never will be one. I do know the scientists involved in this particular mission are right now drooling over the details available in the full resolution image, which I have cropped and reduced to fit on the right. Take a look and you will drool as well.

Want to know where this is? I bet you have already guessed, but if you need help, click on the “read more” link below, where I have also added some comments.
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