Pluto Is Young
The New Horizons science team is stunned by surface features on Pluto and its large moon Charon that cannot be billions of years old.
To cheers from the audience at a New Horizons press conference today (see Space.com video), this global image of Pluto’s large moon Charon was projected on the big screen:
In the video, Deputy Project Scientist Cathy Olkin excitedly described the huge canyons and cliffs, the dark area at the north pole, and the large areas devoid of craters. “So originally I thought Charon might be an ancient terrain covered in craters,” she began. “Many on the team thought that might be the case.” Charon “just blew our socks off” with its falsification of that prediction. Olkin described the things that look young on this largest moon of Pluto:
- The dark area at the north pole, whimsically referred to as “Mordor” by the team, appears to consist of a thin veneer of dark material, as shown by excavation beneath the layer by some craters. The reddish-colored veneer extends beyond the polygon shape of Mordor.
- Across the center from NE to SW, a series of cliffs and troughs are “striking to me,” Orkin said. Extending 600 miles across the moon, this “huge area” could reflect internal processing—surprising for such a small body so far from the sun.
- The area below the troughs has fewer craters, so could have been “geologically active or recently resurfacing that area.” This is reminiscent of Enceladus, which is heavily cratered in its north and active and smooth in the south. “So that’s very exciting to see as well,” Orkin said of Charon.
- Spectacular canyons can be seen at 10:00 and 2:00 on the limb. The eastern one is estimated to be 4 to 6 miles deep—so deep that you can see empty space through a notch at the northern end. “I find that fascinating,” she said. The western canyon is estimated 3 miles deep.
More detailed images of the north and central regions will be forthcoming at 5x this resolution. Summarizing, Orkin said “So it’s a small world with deep canyons, troughs, cliffs and dark regions that are still slightly mysterious to us.”
Pluto Hi-Res Teaser
As if playing “Can you top this?”, veteran planetary scientist John Spencer revealed an image that once again blew everyone’s socks off. It’s the first frame of a high-resolution mosaic from Pluto’s southeastern polar terrain. The detail in this photo, revealing features as small as half a mile across, brought ooh’s and ahh’s of astonishment from the applauding crowd:
Principal investigator Alan Stern, introducing Spencer, said this image “has already given us a big surprise.” Like Orkin, Spencer pointed out features in the 150-mile-wide image that cannot be billions of years old:
- The “most stunning thing” about the whole stunning image is that the scientists have not found a single impact crater seen in the frame. “This means this is a very young surface,” Spencer says, because “Pluto is being bombarded by other objects in the Kuiper Belt.” They guesstimate it has to be “less than a hundred million years old, which is a small fraction of the 4-and-a-half billion year age of the solar system” (in fact, 1/45th that time span). Not only that, “It might be active right now,” he added. “With no craters, you just can’t put a lower limit on how active it might be.“
- The mountains seen, which are “quite spectacular,” are up to 11,000 feet high—incredibly tall for such a small body, rivaling the Sierra Nevada. Spencer explains that mountains this high cannot be supported by nitrogen ice, methane ice or carbon dioxide ice. “You just can’t make mountains out of that stuff.” He believes we are looking at bedrock (or rather bed-ice) of Pluto. Water ice has the strength to support mountains this size. The other ices may just be coatings on top of the mountains.
- Perhaps the biggest upset admitted by Spencer is how young Pluto looks, considering there is no tidal heating. Pluto is the first icy world visited that isn’t orbiting a giant planet. It was easy to explain “strange geological features” on those worlds by invoking tidal heating—deformation by gravitational actions of the giant planet and other moons. That cannot be the case here, where Pluto orbits the sun in isolation.
Gesturing with his hands, Spencer ended with a bizarre notion: “This is telling us that you do not need tidal heating to power ongoing, recent geological activity on icy worlds. That’s a really important discovery that we just made this morning.” The crowd applauded this open-ended statement that leaves unanswered the question, What, then, is capable of powering recent geological activity?
Earlier in his talk, to the crowd’s satisfaction and long applause, Spencer announced the new official name for the heart-shaped bright region visible on yesterday’s global image: “Tombaugh Regio,” named after Pluto discoverer Clyde Tombaugh. The camera zoomed in on Tombaugh’s living son Aldon and daughter Annette who were on hand and appeared gratified by the memorial.
The hi-res frame above comes from day-night line in the south, a bit left of the bottom of the frame. The coming mosaic, covering much of Tombaugh Regio and the surrounding areas (a wide variety of terrains), will be revealed frame by frame as data are downloaded. More images may be released Friday July 17th.
Update: Eric Hand in Science Magazine pointed out additional difficulties with the age of Pluto and Charon. In “Pluto is alive—but where is the heat coming from?” he pretty much ruled out all the traditional sources of heating as he shared the unexpected findings:
- Lack of craters on Charon: “The team also showed off new images of unexpectedly smooth surfaces on Pluto’s moon Charon—which, without an atmosphere, was expected to have an even more battered surface than Pluto.“
- Radioactive heat: “Radioactive elements in both bodies’ interiors could provide some of the heat needed for geological mountain building or ice flows that repave the surface. But Pluto, and especially Charon, are far too small for this heat to persist.“
- Impact heat: “The giant impact thought to have formed the two worlds could also provide a source of energy, but that probably happened billions of years ago.“
- The volatile veneer: “Yet if these layers are too thin, they would be lost completely relatively quickly as they sublimate into the atmosphere and erode into space, Stern says. That means that there must be a way of replenishing these more volatile ices from within Pluto’s interior—perhaps through volcanoes of ice, called cryovolcanoes.” The team will be actively searching for evidence of them.
- Special pleading: “Collins is excited because there is no way to explain the activity with conventional models of heat loss. ‘If the Charon-Pluto impact happened more recently, all the problems would be solved,’ he says.” Titan expert Jonathan Lunine doesn’t like that appeal to special circumstances. “‘How do you keep these things warm for so long?‘ he asks. But he would rather find a mechanism besides a more recent impact event, which he calls ‘special pleading.’ A giant impact is more likely to have occurred near the start of the solar system 4.5 billion years ago, when the Kuiper belt—the distant shell of icy bodies in which Pluto resides—harbored more potential impactors than it does today.” But then Lunine did some special pleading of his own: “But Lunine says it could be that the dynamics of the Kuiper belt are different from those in the rest of the solar system.“
- Evolving notions: “The mountains—and their implication of mountain-building activity—runs counter to the expectation that Kuiper belt objects are cold, pristine relics. ‘We talk about these things as time capsules from the early solar system,’ she [Nancy Chabot] says. That notion must evolve, she says. ‘Even though they are primitive bodies, they are also active bodies.‘”
Water ice at Pluto’s temperature should be as solid as rock. Lunine suggested that adding ammonia might make it flow easier at lower temperatures. Why, though, would it form sharp-peaked mountains as seen in the image? On The Conversation, David Rothery points to canyons and chasms on some other moons, like Titania and Ariel at Uranus, or Tethys at Saturn. It seems obvious, though, that adding more instances of mysteries won’t help. Besides, those moons are subject to tidal forces not available to the Pluto system. Clearly the scientists are grasping at straws to explain how these distant, cold, “primitive” bodies look so young.
We didn’t expect our predictions (7/09/15 commentary) to be confirmed so quickly. Well, maybe we did.
“Pluto will show active geology, including ice volcanoes or geysers, and evidence of resurfacing (e.g., few craters or smeared craters) that will challenge the belief it is billions of years old.” The second half is clearly confirmed; perhaps evidence of current activity will turn up in future hi-res images. (Recall it took a year to detect the Enceladus geysers after Cassini arrived at Saturn.). Spencer’s explanation undermines tidal heating as a plausible force to keep Enceladus, Triton, Europa and perhaps even Io active for billions of years.
There’s a hint that our prediction of atmospheric escape rates is likely to be confirmed, since nitrogen was found farther from Pluto than thought (see 7/14/15).
We predicted that the moons would challenge ideas that they formed from a collision. The initial Charon image may be too equivocal to call that prediction a success yet, but unless Charon formed very recently, it seems unlikely there would be vast crater-free areas that are geologically active or resurfaced. We’ll see how this develops as images of the smaller moons come in.
It’s a bit early for the hydrobioscopy craze to set in, but we expect prediction #4 (claims about life) will come soon now that active geology on a world of predominantly water ice is being considered seriously.
For those who would counter that “100 million years sure doesn’t fit a Biblical timeline,” we remind you that Spencer said that the features cannot be older than 100 m.y. He was setting an upper limit, not an absolute age. He followed by acknowledging that you can’t put a lower limit on the features; they could be ongoing today, for all scientists know. One thing is for sure: 100 million years is far, far less than the A.S.S. of 4.5 billion years, just 1/45 of it. What happened during the other 44/45ths of the assumed timeline? Are they real? Why would human beings live in a special time when active geology is observable on Pluto and Charon? The simplest explanation is that these worlds are young; and if young, the supports for the Bearded Buddha (Darwin) come crashing to the ground.
These are stunning revelations that cannot be denied. The planetary scientists are both surprised and excited. (Somehow, they enjoy being shown things that look young in spite of their clear predictions they would find cold, dead worlds.) The most stunning (read: crazy) idea is that active geology on distant, icy worlds can be sustained without any known force like tidal heating to do it, and can continue for 4.5 billion years! This defies the laws of physics. But was Spencer or anyone else on the team going to seriously consider the idea that the billions-of-years age is wrong? Never! The thinking is, We know these worlds are old, so what do you know? It’s exciting to realize that geological activity can take place on a small body for billions of years. That’s why we call the A.S.S. the Law of the Misdeeds and Perversions that cannot be revoked (cf. Daniel 6:8-9). But who are you going to believe, the secular scientists that reporters lionize, or your lyin’ eyes?