First Contact (10 page)

“Antonio just started showing me a bunch of other stuff that he had on his computer, and all of a sudden—boom—up came this picture of this little vial,” said the low-key Bada, suddenly animated. “I said, ‘What's that?'”

“Stanley told me it was extract from one of his original experiments that he'd saved,” replied Lazcano.

“I felt like he hit me over the head with a rock and knocked me on the ground,” Bada continued. “I was so stunned, I said, ‘What do you mean?'”

“Well,” Lazcano said, “Stanley just reached up in his office on the bookshelf and got down this cardboard box and pulled out another little box and said, ‘Yes, here's one of the portions of my first experiments.'”

It all then came back in a flash. Bada remembered taking that bigger box of old vials out of the lab, granting it no particular importance and, he hoped, putting it in storage rather than in the trash. Alternately very excited about what might well have been in the box and heartsick that he
may have tossed it out, Bada raced with Lazcano back to San Diego. They sped to the lab and, with profound relief, almost immediately found the box—still filled with vials featuring Miller's careful writing and small bits of brownish tar, including some from his most famous experiments. The two had struck gold, and they knew it. Their mentor would be directing their scientific paths once again.

“I guess what he did was take a sample out [of each flask], dried it down, and stuck it in those vials and just figured, well, there is probably not enough in there to analyze, but I'll save it anyway,” Bada said. “Today, with the modern analytical methods you have available, that little amount of resin blows our instruments off the scale.”

The Miller-Urey experiment was back, fifty-five years after being first conducted, and would soon be opening the door once again to new insights into how the building blocks of life may have been assembled. Unknown even to his colleagues, Miller had conducted some parallel experiments using the same gases but, he noted at the time, in the kind of steam-rich, lightning-charged environment found in a volcano. Bada recruited two other former students in Miller's Scripps lab—Danny Glavin and Jason Dworkin—who had gone off to work at NASA's Goddard Space Flight Center, where they had available precision instruments Stanley Miller could only dream of. The two analyzed the results from eleven vials of residue from those “lost” experiments using their cutting-edge lab—overflowing with compound separation and detection equipment—and discovered that the lost-and-found-again samples had produced an even more impressive array of amino acids than Miller had ever detected, twenty-two in all. That second, unheralded experiment also involved this highly significant modification: It was designed to simulate the chemistry and dynamics that occur at the mouth of a volcano rather than in the early Earth atmosphere. Suddenly the Miller-Urey experiment was pertinent again, because it showed that essential precursor amino acids could have been forged in the mouth of a volcano on early Earth as now, even if the surrounding atmosphere was considerably different. An article was quickly published in the authoritative
journal
Science
outlining the recovered results and the case for volcanoes as possible stovetops for cooking important ingredients for life. The article came out in late 2008, around the time that Mount Redoubt, one of many volcanic sites in a line from coastal Alaska out into the Pacific, was erupting with fireworks, lava, and a vast ash cloud. Bada saw footage of the eruption and was struck by the amount of lightning present.

Critics of Stanley Miller had often pointed to his use of an electric sparker as a highly implausible re-creation of the dynamics of early Earth. But, as it turns out, pioneering research into volcanic lightning is making his sparker seem not so crazy after all, and now a new generation of scientists believe volcanoes may offer up clues to the process of preparing the Earth for life.

Volcanoes spit out molten rock, water, and gases from deep in the Earth and, in the superhot cauldron of its mouth, chemical reactions can occur that would lead to formation of those otherwise absent amino acids, as well as transform some molecules into forms more conducive to biology. For instance, the tight triple bonds of the most common form of nitrogen, an element essential for life, are broken in the heat of a volcano and can then combine with other elements and form useful compounds. For the amino acids, the newly formed precursor compounds in the volcanic furnace would then undergo additional changes in the waters assumed in this scenario to surround the volcanoes (through a process discovered 150 years ago by German chemist Adolph Strecker) and would gradually emerge as fully formed amino acids. They would then settle in ponds and tidal basins, where they would get concentrated through the work of the sun and become available to someday be incorporated into RNA or DNA.

So with this new incarnation of Miller-Urey research in mind and Mount Redoubt predicted to erupt again soon, I headed to Alaska to meet up with a specialist in lightning. Bada and his colleagues are squarely in the world of astrobiology, but my lightning expert, Ronald Thomas of New Mexico Tech in Socorro, is not. He has spent years chasing after thunderstorms to better understand how and why lightning strikes as it does. He
was able to interest the National Science Foundation in a most unusual proposal a few years ago, one that was inspired by his study of the Mount St. Augustine volcano, which erupted in Alaska in 2006. Lightning, observers have long known, tends to accompany volcano eruptions—Pliny even wrote about the lightning display at Mount Vesuvius when it blew and destroyed Pompeii. But research into how or why lightning might accompany eruptions has, by all accounts, been limited. So Thomas (who teaches electrical engineering) entered the field, and his findings could have real significance for the Miller-Urey legacy and the origins-of-life field.

During the Mount St. Augustine eruption, Thomas teamed up with Alaska Volcano Observatory scientist Steven McNutt, who had initially noticed the heavy lightning associated with the event. When Mount Redoubt was preparing to go off, McNutt contacted Thomas, who rushed up to Alaska's Kenai Peninsula to set up the antennas that would monitor the eruptions. His technique was simple but novel: He was going to collect radio waves from the erupting volcano, which would contain the information he needed about the lightning being discharged in and above the volcano. Especially early during an eruption, ash and rock can hide the lightning, and those early fireworks seemed to be the most interesting. Their team set up a Lightning Mapping Array with four stations two months prior to what turned out to be a delayed eruption. Each station, explained one team member, has “basically a simple TV antenna set to pick up channel three—the frequency that lightning radiates.”

When the volcano first blew in late March 2009, the instruments set up by Thomas and his colleagues found that lightning flashes accompanied every single one of the more than twenty major eruptions that occurred over thirteen days. What's more, they detected an unusual kind of lightning in the early moments of the eruption: a “constant lightning” that contained an extraordinarily high number of short bursts of 40 to 100 feet. They've never actually been seen, but Thomas imagines they would dance like enormous sparks from a monumental spark generator. The energy being released was monumental, a mass of very large electrical sparks that, if
similar to other recent observations of constant lightning, glowed orangered at the peripheries and a deeper red close to the mouth. Thousands of small flashes each set off radio impulses that flew across the inlet and were captured by the waiting receivers, which then drew a picture in graphs of what was happening. “The really intense phase of constant lightning went on for twenty to thirty minutes,” Thomas told me. “We saw more lightning than we'd generally see in a major thunderstorm.” His fellow researcher McNutt said those lightning strikes at the start of the Redoubt eruption lasted only 1 to 2 milliseconds and were “a different kind of lightning than had ever been seen before.” Quite obviously, a great deal of energy was being released, exactly what was needed to “spark” the gases and water erupting from the volcano and change them in ways that would produce amino acids.

The radio monitors set up by Thomas's team were all on the far side of robin's-egg-blue Cook Inlet, about forty miles away from Mount Redoubt. They had wanted to place them closer, but the combination of Redoubt's location on protected federal land and the obvious dangers of being too near the volcano made that impossible. By correlating the millisecond differences in their flashes and triangulating the distances from the radio monitors across the inlet, Thomas was able to map and measure the lightning strikes inside the ash clouds in a new way—showing where the lightning originated and how it spread. He had begun that kind of monitoring at the Mount St. Augustine eruption in 2006 and had seen some of the same phenomenon, but it was during the Mount Redoubt eruption that the “constant lightning” phase was confirmed and better characterized. For a man who has witnessed a lot of lightning, Thomas was impressed. “I'm not sure I've ever been so excited by lightning before,” was his conclusion.

As the team waited for possible further eruptions, McNutt proposed a trip to the mouth of the still-steaming volcano in a small, six-seater airplane. We approached ten-thousand-foot Mount Redoubt from the back, and were promptly introduced to the volcano mouth, hissing and spitting a short distance from the peak. From some angles, the volcano still appeared
to be smoldering inside with a yellow-orange glow. Not surprisingly, we tend to think of volcanoes in terms of the dangers posed by shooting rock and flowing lava, noxious smells, ash shower, and acid rain—the effects we can see on the Earth's surface and its creatures. But flying over the still-scalding mouth and the lava slide forming just below, volcanoes come across as the endpoint of a tortured pathway from the innards of the Earth up to the surface. They deliver molten rock as hot as 2,000 degrees Fahrenheit and high-pressure gases from a place that seldom enters our minds: the rocky mantle below the Earth's crust, where the frictions and pressures of the always jostling continental plates, combined with the heat emanating from the planet's liquid outer core, can become so intense they, well, melt rock. Even a clouded peek into that world is unsettling; the power is just so unimaginable. Getting an up-close glimpse of the power and magnitude of a volcano—even without its supercharged lightning bursts—made the kind of early Earth chemistry proposed by Miller seem entirely possible.

As we circled the volcano, we could also see a thin, cloudlike haze and plumes above the peak of what looked like a gigantic steam grate at the volcano's mouth. The haze, Thomas and McNutt explain, is sulfur dioxide (which erupts with the magma and can lead to damaging acid rain) and the plume is largely H
₂
O. Magma contains huge quantities of water—more than in a thunderstorm, Thomas said—released during the melting of the rocks. If the airplane windows were opened, we would also have smelled the rotten-egg odor of hydrogen sulfide and would have been bathed in methane and nitrogen as well. The violence of a volcano's eruption is largely a function of the gases present; through their natural expansion, they determine just how explosive the eruption will be based on what gases are present and in what quantities they concentrate. But the gases that emerge are not necessarily the gases that settle on the surrounding landscape. The great temperature and pressure changes at eruption and all those lightning bolts of highly charged electricity set off chemical reactions that modify or transform the gases. That's the cascade of changes that Stanley Miller identified decades ago, and that Bada and his colleagues recently found to
be even more enhanced in Miller's initially unpublished but now available experiment designed especially for volcanic conditions.

Earth has always had volcanoes of all kinds and in all climates: Volcanologists estimate there are about six hundred active ones today, and believe there were many more in the distant past (and on other planets like Venus and Mars). Some of those Earthly volcanic ranges, including the ones that formed the Hawaiian Islands and Iceland, bring up gases more directly from the scalding outer core, lessening their time in the cooling mantle. They also provide the kind of protective micro-environments that Bada and Lazcano believe played a major role in the origins of life, when much of the globe was covered in oceans only dotted with volcanic islands. The building blocks for the formation of amino acids and then proteins were all there, and Miller and his disciples showed in the lab a pathway for the process to work. We will never know for sure how that initial transformation from nonliving to living occurred because the evidence is gone. But we can know how the building blocks were formed from simpler, more elemental molecules.

Several months after Mount Redoubt calmed down, Bada came across some other potentially interesting vials in the old Miller cache. The one that most intrigued him was the brown residue produced by another experiment in 1958, one that used different gases than the original iconic Miller-Urey experiment. The 1958 model eliminated the hydrogen and added carbon dioxide, thereby responding to critics who said Miller was using the wrong gases to replicate atmospheric conditions on the early Earth. Miller also added the foul-smelling hydrogen sulfide that generally accompanies volcanic explosions and again sparked the mix with lightning-like electricity. The results, Bada said, were even more remarkable than the earlier experiments—with a greater number of amino acids produced and a better lineup of isomers, compounds with the same molecular formula but with different structures.

“I stand back and look at what's happened and I'm still dumbstruck,” Bada said. “We've had the results of these experiments for at least ten years
yet we never knew they existed. It's incredible new information and really shows Stanley's influence is with us today.”