The Second Kind of Impossible

by Paul Steinhardt

  When Glenn checked the chemical composition of the curious white chips with his electron microprobe, he became even more animated.

  “The chips are cupalite!” Glenn announced excitedly. We looked at one another and half laughed and half cheered. “Unbelievable!” I shouted.

  Cupalite, along with khatyrkite, was one of the metallic alloys found in the original museum samples that had made everyone, including Glenn, dismiss them as fake. Finding cupalite chips buried inside the chondrule, the oldest part of the meteorite, was the most direct evidence yet that the meteorite’s aluminum-copper alloys formed in space 4.5 billion years ago when our solar system was in its infancy.

  * * *

  FLORENCE, OCTOBER–NOVEMBER 2011: When I circulated the news about Grain #121 to the team, effusive praise and congratulations for Luca began to pour in from everyone, including our anonymous benefactor, Dave. They were all beginning to recognize that Luca was, indeed, L’Uomo dei Miracoli, as I affectionately called him. The Miracle Man.

  New discoveries kept coming. L’Uomo dei Miracoli struck again with Grain #122. I had been sending the team regular bulletins about Luca’s progress. Now, I was issuing another update for the third time in less than six weeks:

  It seems hard to believe that only 10 days have passed since Report #2 and there is already important news to report: Icosahedrite has been discovered in a third grain recovered from the Koryaks, this time from a different location: Will’s Hole.

  My report emphasized that the three meteoritic grains that were now making scientific history had been found in three different locations along the Listvenitovyi. Marina and Sasha had recovered Grain #5 from the Green Clay Wall; Grain #121, the grain with the chondrules that had intrigued Glenn, came from the Downstream Green Clay Wall; and the latest discovery, Grain #122, was recovered from Will’s Hole. Only the last site, Will’s Hole, had blue-green clay.

  The fact that the samples came from different types of sites distributed over hundreds of meters was informative. It meant that all of the sample bags from all of our dig sites could be potential sources of meteoritic material, not just the bags that came from sites containing blue-green clay. That meant Chris Andronicos had been right when he advised us to broaden our search to other areas. I was once again reminded that Chris was a crucial member of our team. Without him, we might never have retrieved so many promising samples.

  I thought Luca’s discoveries would be especially gratifying news for everyone who had continued to work so diligently during the expedition, battling the nearly frozen clay and often plunging their bare hands into freezing water after all of our shovels had broken.

  Then ten days later, I sent out yet another report describing yet another miracle from L’Uomo dei Miracoli. Grain #123, also from Will’s Hole, was significant because it contained the largest grain of icosahedrite seen to date that was in direct contact with meteoritic material.

  The importance of such a finding cannot be overstated. Before the expedition, Lincoln and Glenn had bemoaned the fact that we could not find indisputable evidence that the quasicrystals in the Florence sample were in contact with meteoritic minerals. We needed that evidence, they said, in order to help prove our case that the quasicrystals had formed naturally. Now, with Grain #123, we finally had a large and unambiguous piece of evidence.

  In the image above, the quasicrystal, icosahedrite, is the chunk of material in the upper right. It is physically connected and enmeshed with the silicates below.

  The miracles continued as Luca combed through the bags. He soon identified three more grains—#124 from Will’s Hole and #125 and #126 from the Primary trench—all of which appeared to be meteoritic. With his incredible string of discoveries, Luca’s title was now firmly established. L’Uomo dei Miracoli!

  * * *

  PASADENA, FEBRUARY 2012: The grains Luca had found were sent off to Caltech for John Eiler and Yunbin Guan to analyze with the NanoSIMS.

  By now, based on our earlier tests of the Florence sample, our leading hypothesis was that the aluminum-copper alloys had formed in space and arrived on Earth as part of a carbonaceous chondrite meteorite. But we were always on the lookout for contradictory information. If we were to ever find an example in which icosahedrite was attached to ordinary terrestrial minerals, that single exception would be enough to force us to rethink our entire theory. Everything we thought we understood about the extraterrestrial origin of icosahedrite would be thrown into doubt. So it was crucial to repeat the oxygen-isotope NanoSIMS test on the silicates found in each and every sample recovered from Kamchatka.

  Luca was working in overdrive, so I had become accustomed to receiving fast, accurate results. Shifting focus to Caltech’s spectrometer, though, was like being forced into the slow lane. The equipment was always booked several months in advance with a backlog of important research waiting to be done. It was also constantly breaking down and in need of repair. So it would be another long six months before we would begin to get the first reports.

  Once the results finally began trickling in, they proved without a doubt that the silicates had exactly the same oxygen isotope ratios as the Florence sample, which, in turn, had the same signature as a classic CV3 carbonaceous chondrite.

  John Eiler was one of the geologists who had initially warned me not to make the expedition. There was essentially a zero chance, he said, of finding any more meteorite samples on our expedition to Kamchatka. But the best scientists always enjoy being surprised and discovering something unexpected. So despite his initial doubts, or perhaps because of them, John was excited to send me the good news that proved he had been mistaken.

  * * *

  HOUSTON, TEXAS, MARCH 2012: One month after the Caltech measurements were completed, Glenn shared our phenomenal results with other meteorite experts throughout the world at the annual Lunar and Planetary Science Conference (LPSC). The team was confident Glenn would be our best representative. He was well known and well respected in the LPSC community.

  Glenn went to the meeting armed with all of the impressive evidence we had collected both before and after the expedition. He met with the Nomenclature Committee and made the forceful case that we had discovered a new meteor impact. It was crucial for us to obtain their official imprimatur in order to convince the rest of the meteorite community that our finding was legitimate. But gaining such acceptance is often an uphill battle. The committee is notoriously ultraconservative and super-finicky.

  Glenn must have bowled them over because the committee immediately accepted his case that the grains were meteoritic. They also agreed to assign the meteor the official name we proposed: Khatyrka, in honor of the river we had managed to drive and float across in our two behemoths.

  Five months later, Glenn took charge of drafting the first scientific paper about the expedition results, which was published in the prestigious journal Meteoritics & Planetary Science (MAPS) on August 2, 2013. The paper combined valuable contributions from each member of the expedition, as well as from Lincoln Hollister, John Eiler, and Yunbin Guan. Some members of the team had moved to other institutions since the expedition. Our team was now spread around the world in Florence, Boston, Moscow, Washington, D.C., Houston, West Lafayette, Pasadena, Johannesburg, and Princeton.

  We were anticipating a fair amount of skepticism because of the unusual aluminum-copper alloys found in our samples. So Glenn had made sure that our MAPS paper was absolutely meticulous. It was full of images and exceedingly detailed, including a description of the pristine clay layers in which the samples were found and the exhaustive, quantitative measurements of mineral compositions and isotope concentrations that had been taken from each sample.

  The paper, entitled “Khatyrka, a new CV3 find from the Koryak Mountains, Eastern Russia,” established the existence of a new meteorite and provided new evidence for the natural provenance of a number of aluminum-copper metallic minerals, including the first-known natural quasicrystal, icosahedrite.

  The meteorite commun
ity had no trouble accepting the conclusion that the silicates in our samples were meteoritic. The oxygen-isotope tests were unambiguous proof of that, as far as anyone was concerned. But as always, it was the natural origin of icosahedrite and the other aluminum-copper minerals found in the Khatyrka meteorite that were more difficult for some to accept. Like other types of geologists, meteorite experts had always been taught that minerals with the symmetry of an icosahedron were impossible. So were the strange metallic aluminum alloys we were reporting. Nothing like this had ever been seen before in meteorites. Glenn’s presentation at the LPSC meeting and the MAPS paper marked the beginning of a discussion about quasicrystals and metallic alloys that would last for years.

  Despite the assemblage of evidence in our scientific paper, a few meteorite scientists remained vocal skeptics of our conclusions. We never criticized any of them for doubting our claims. After all, Lincoln and Glenn had initially reacted the same way when Luca and I brought them our initial discovery in 2009.

  Most of the doubts tended to melt away whenever we were given the opportunity to present our remarkably thorough test results. But for those who never seemed to take the time to learn about all of the detailed evidence, our conclusions were considered impossible. They preferred to stick to their view that quasicrystals and alloys containing metallic aluminum could not be made by any natural process whatsoever, either on Earth or in outer space.

  Three years after our paper was published the discussion was still raging in certain pockets of the scientific community. So Glenn, being a colorful debater, decided to engage in more public discussion. He prepared a poster presentation for the 2015 Lunar and Planetary Science Conference, which was attended by ten thousand scientists. Glenn stood alongside the poster at the convention and personally explained important details about all of the evidence we had collected since his first presentation in 2012.

  To make the evidence even more accessible, the team prepared a handout to accompany Glenn’s poster with a list of FAQs and answers. In a typically theatrical flourish, Glenn challenged anyone to come up with a plausible alternative explanation for all of the evidence we had collected to prove the existence of a natural quasicrystal and metallic alloys.

  The only group that attempted to respond to the challenge was a team of Russian geologists who had attempted their own expedition to Kamchatka after hearing about our success. They prepped for the expedition by meeting with our Russian colleague, Valery Kryachko. Even so, their trip to the Listvenitovyi Stream turned out to be an utter failure. They never found a single grain of meteorite, quasicrystal, or aluminum-copper alloy in any of their panned material.

  Instead of questioning their own methodology, the team responded to Glenn’s challenge by publishing a paper asserting that, despite mountains of documentation, our findings were mistaken. The metal alloys in our samples had to be synthetic, rather than natural, they claimed. They floated the idea that our samples had been accidentally created by gold miners as a result of the dynamite blasts they set off while loosening clay to pan for gold. The blasts, the Russian team proposed, could have shredded nearby tools or piping or some other unknown mining equipment composed of aluminum alloys. Then, bits of that metallic material could have been propelled into nearby rocks at high speed. Included in the rocky targets, they supposed, were the remains of a CV3 carbonaceous chondrite meteorite, which, just like the well-known Allende meteorite, did not originally contain any metallic alloys. Their conclusion was that the accidental fusion of exploded man-made metal with an ancient meteorite created our samples.

  While imaginative, the concept does not hold up under scrutiny.

  First, the Russian team could not produce a single metal implement used by gold miners with the right chemical composition to explain either the quasicrystals or the aluminum-copper alloys we discovered in our sample. In fact, while investigating the use of aluminum-copper alloys, I had discovered that metals with such compositions are far too brittle for any kind of practical use. It is true that aluminum-copper alloys with only a few percent of copper added to aluminum, or vice versa, are commonly used. But the alloys found in the Khatyrka meteorite, which included 50-50 or 60-40 mixtures of these metals, have no known industrial applications for one simple reason: They are too brittle.

  Second, if the blast proposal were true, one would expect to have found metal alloys fused with ordinary terrestrial minerals. Terrestrial minerals are exponentially more abundant than meteoritic material at the Listvenitovyi. In fact, even before the Russians proposed their blast idea, we had been searching systematically for such examples to test our own meteorite hypothesis. We never found an example, and neither did the Russian team. Not a single one.

  Third, the Russian blast idea did not account for the quasicrystal grain totally encased in stishovite that Luca had found in the Florence sample. Stishovite is a silicate that can only be created at ultra-high pressures. Those pressures could never be created by metal shrapnel propelled by a dynamite blast.

  Since it could not have been created by the blast, the stishovite must have been part of the meteorite before the blast, according to the Russian team’s logic. The metallic aluminum alloy, which the Russians claimed was synthetic, would have then been propelled by a blast into the meteorite. But if that had been the case, the stishovite grain, which would already be part of the meteorite, according to the Russian hypothesis, would have a large hole where the synthetic alloy had pierced through, and there was absolutely no evidence of that.

  Fourth, the blast hypothesis could not explain why some of our grains were found in pristine clay buried deep under the surface, which had apparently sat undisturbed for thousands of years. No dynamite blast could have sent bits of metal from nearby tools hundreds of meters downstream and through so many layers of sediment in a claybed, especially not without leaving a lot of other obvious damage in the area.

  In the end, these and other weaknesses we pointed out in the Russian team’s explanation made it clear how strong our case for a natural origin was and how difficult it was to find any plausible alternative.

  Our team would have much preferred that the Russian scientists had succeeded in finding additional meteoritic samples, since that would have provided more scientific data. But I had always known it would be difficult for any other group to duplicate the success of our expedition because they could not hope to replicate the single most important component of our success: the people on our team.

  Others could dig and pan as much as we did, but they would never have diggers as committed or as careful as Will, or a panner as experienced and as skillful as Valery. They could never have a meteorite expert as qualified as Glenn. They could never hope to duplicate Valery’s, Marina’s, and Vadim’s decades of experience working in Kamchatka and other areas with natural ores. They would never need their own mapping team to study the geological history of the area, because Chris and Mike, with support from Marina and Sasha, had already done all of that hard work for them. And perhaps most importantly, they would never find anyone with nearly the knowledge, talent, and all-out, no-holds-barred dedication as Luca.

  I am especially proud of the fact that our team has kept its scientific standards sky-high and has constantly challenged its own conclusions to avoid becoming overconfident or careless. Lincoln Hollister has been a model for us all in this regard. More than any outside individual or group, we have always been the toughest critics of our own work. We question and challenge one another over and over to make sure no details or theoretical possibilities are missed.

  In the years since the expedition, we have methodically eliminated all of the various possible explanations for how our samples could have been created by natural terrestrial forces or accidental industrial or mining activities. But there has always been a nightmare possibility that we have returned to over and over again: Could we be the victims of an elaborate ruse?

  The NanoSIMS oxygen-isotope measurements confirmed that the silicates were from a CV3 carbonace
ous chondrite meteorite, dating back to the birth of the solar system. But the NanoSIMS could not be used to test the metallic alloys because the alloys contained no oxygen.

  Could a devious person combine genuine Allende-like meteoritic material with synthetic aluminum-copper alloys, expose the mixture to some combination of high pressure and temperature and produce samples like those we recovered?

  The first problem we ran into while exploring that outlandish scenario was the same one that made the Russian blast idea so untenable. There are no readily available metals with the same compositions of aluminum and copper that were found in our Khatyrka samples. The alloys are simply too brittle to ever be of any industrial or commercial use. Fakers would have had to synthesize the peculiar metal combinations on their own, beginning with pure aluminum and copper. They would have had to engineer that process before 1979, when Valery recovered the first samples from the Listvenitovyi. A problem with that particular timing, of course, was that it would have been several years before Dov Levine and I had considered the possibility of quasicrystals and before they had been discovered in the laboratory. So that would mean there would have been no motivation for creating metallic alloys with such peculiar chemical compositions. But assuming the faker did so anyway and mixed them with real meteoritic minerals, he would have had to place the fruits of his devious labor in an obscure stream in the remote Koryak Mountains and bury them deep in thick clay, not knowing if anyone would ever discover them.

  While all of that was ludicrously improbable, we nevertheless went through a brainstorming exercise to see if we could design a procedure to create the type of grains we had observed without producing any tell-tale signs of fakery. Try as we might, none of us was ever able to come up with anything close to a workable theory.