I trekked to a nuclear crater to see where the Atomic Age first began

75 years ago, the world changed forever with the first detonation of a nuclear device in the New Mexico desert.

I am standing at the gateway to Armageddon, and I’m locked out.

“This key doesn’t fit,” my guide says, jiggling a standard-issue padlock, as if that might help. “They must have changed the lock.”

We look at each other with “Well, now what?” expressions. We have just spent a half hour in a pickup truck, bumping 17 miles across a scrub-strewn landscape from the north gate of New Mexico’s White Sands Missile Range. Now we are staring at a chain-link fence that curves away from us in both directions, creating a mile-long circle around one of the most significant sites in human history: ground zero of the first atomic bomb blast.

It’s hot here in the treeless, open-air oven the Spanish conquistadors called Jornada del Muerto (Journey of the Dead Man), but not as hot as it got 75 years ago. At precisely 5:30 a.m. on July 16, 1945, a fireball half-again as hot as the surface of the sun scorched the earth of this basin and ushered in the atomic age.

Now I’m worried that I’ve come all this way in vain. But Drew Hamilton, who’s been a White Sands public affairs liaison for 10 years, has a plan.

“They have a spare key at the fire department,” he says. “We can borrow it.”

“Great!” I say. “Where’s the fire department?”

“Back at the gate!” he replies merrily.

My enthusiasm is deflating, but I decide to channel Hamilton’s gung-ho attitude. We climb back into the white pickup and jostle our way back.

I watch the barren landscape slide past. The milkweed and agave are a rushing blur against the blue Sacramento mountains in the distance. I’ve come a long way to get here, but that first atomic bomb had an even more circuitous journey.

In the early 1940s, U.S. intelligence harbored a terrifying secret: Germany was feverishly trying to develop a nuclear bomb.

In the United States, President Franklin Roosevelt—spurred by an alarming letter from Albert Einstein—authorized an all-out nuclear program. In charge of building the nationwide network of top-secret infrastructure was the Army’s General Leslie R. Groves, an engineer who’d just overseen construction of the Pentagon. Groves hand-picked theoretical physicist J. Robert Oppenheimer to head the scientific team. The actual testing of the device was to be led by Harvard physicist Kenneth Bainbridge. (Here's how Einstein's work on a refrigerator led to the letter to Roosevelt.)

From Washington State to Tennessee, some 130,000 Americans were employed in the effort, virtually none of them with any knowledge of what they were working on. The nerve center of the massive project was the sleepy town of Los Alamos, New Mexico, atop the Pajarito Plateau. There, the quaint buildings of a boys’ school—attended by Oppenheimer as a child—were converted into a campus where scientists and engineers theorized, designed, and built the components of the device that became known as the “Gadget.”

And a hundred miles to the south, in the remote desert south of Albuquerque, a bare-bones facility was built for the final assembly and testing of their combined efforts. The project was called Manhattan. The first blast was called Trinity.

Why Trinity? Oppenheimer, a bookish sort of guy, came up with the name, but his explanation was vague, says Jim Eckles, now retired after 30 years as a White Sands public information official but still its go-to guy for all things Trinity.

“He said he wasn’t sure,” says Eckles, “but he knew he’d been reading some poetry by John Donne at the time, and one line stuck with him: ‘Batter my heart, three person’d God.’ From that he somehow moved on to Trinity.”

Eckles and I are chatting in the front room of his home in Las Cruces, a town that’s pressed along the southwestern end of White Sands. He’s something of a legend at the range, and he still volunteers to answer questions during the two days a year that the Trinity site is open to the public—the first Saturdays in April and October.

“The White Sands location wasn’t the automatic choice for Trinity,” Eckles says. “Several other places were considered: Colorado, the barrier islands off south Texas, and even one of the Channel Islands off southern California. But in the end, White Sands was in the middle of nowhere, it was relatively close to Los Alamos, and there was already a government bombing and gunnery range here.”

The Trinity test originally had been scheduled for July 4, but that was pushed back as the experts tinkered on the Gadget.

The mechanics of creating the biggest explosion since Krakatoa erupted were at once both mind-numbingly complex and stupefyingly simple. Basically, the heart of the globe-like, five-foot-wide Gadget was a 13-pound, softball-size sphere of plutonium, a highly radioactive and relatively unstable element created from uranium in a nuclear reactor. That softball needed to be compressed to the size of a golf ball, at which point the sphere would attain critical mass and erupt in an uncontrolled, cataclysmic explosion.

How do you make a plutonium softball into a nuclear golf ball? You place it at the center of a larger sphere, surround it with 5,000 pounds of high explosives—32 separate bombs—and blow them up at the very same millisecond. The pressure of the blast coming from all sides will crush the plutonium like a super-dense, radioactive meatball. There were no digital switches in those days, so all the little bombs had to be wired to a single control, located in a bunker 5.5 miles to the south. And every wire had to be exactly the same length.

In concrete bunkers as close as 800 yards from ground zero, scientists hooked up oscilloscopes, radiation detectors, and lots and lots of cameras, including Mitchell 35mm movie cameras—the same type that six years earlier had filmed Gone With The Wind—and Fastax cameras, snapping away at 10,000 frames a second.

July is the rainy season in New Mexico, but long-range forecasts indicated the 16th would be relatively free of precipitation. The date was set. On July 12, a Packard sedan left Los Alamos, winding along mountain roads and across empty expanses on the way to ground zero. In the back seat, packed into a small box perforated with what looked like breathing holes for a pet, were the two halves of the Gadget’s plutonium core.

The next day, Friday the 13th, a truck left Los Alamos carrying the five-foot-wide sphere to White Sands. Zero hour was less than three days away.

Last eyewitnesses

“Let’s stop someplace before we go get that key,” says Drew Hamilton. We follow a dusty road toward a small, dark house about two miles from ground zero.

We pull up to the Schmidt homestead, built by a rancher in 1922 and commandeered by the Army in 1944. There is a photo of a sergeant named Herb Lehr walking through the front door, carrying the bomb’s plutonium core with all the nonchalance of a kid toting his lunch box. In that room, the world’s first atomic explosive device was assembled.

We don’t have a key to get into the ranch house, so I go from window to window, cupping my hands on the glass to get a look. Seventy-five years ago, through plastic sheets nailed to the windows to keep the desert dust out, I would have seen a team of three scientists gingerly assembling the elements of the core.

On Saturday the core was inserted into the Gadget. A heavy-duty hoist lifted the assembly to the top of a 100-foot steel tower, fabricated by a Pittsburgh company and assembled by Army engineers.

Next came the final preparations; wires attached, circuits double-checked. Most of the telemetry equipment and ignition circuits had already gone through a dress rehearsal in May, when the staff blew up 100 tons of TNT just a few hundred yards from ground zero. Nobody there had ever seen, heard, or felt an explosion of such violent power.

We continue our return trip to the fire station. Even in the air-conditioned truck, New Mexico’s intense heat filters through. I try to imagine being a G.I. from Chicago or New York, dodging rattlers and hiding from the incendiary sun whenever possible.

Alas, there is no one I can ask about those experiences first-hand. When I started planning this story in late 2019, I had leads on a few living survivors of Trinity. But COVID-19 intervened on my plans to visit them, and as the weeks and months went by, the sad news filtered in.

I had hoped to ask Bob Carter, who’d been a low-level physicist at Los Alamos, about his unauthorized, late-night motorcycle ride—with a woman friend holding on—to watch the blast from a remote hillside. He died April 7 at 100 (not from the coronavirus).

I was too late to talk with Fred Vaslow, who used his last gasoline ration coupons to drive down from Los Alamos with some pals. They watched the blast from a hill, saw the cloud coming toward them and, as he told another interviewer, “got the hell out of there as fast as we could.” He was 101 when he died in March.

And I just missed getting to talk with chemist Robert J.S. Brown, 95, who remembered square dancing in Los Alamos with Enrico Fermi, the physicist who’d accomplished the first controlled nuclear reaction in Chicago.

And so, as the 75th anniversary of Trinity arrives, not one person survives who stood on the desert floor or its surrounding hills that rainy morning.

The big bang

The test had been scheduled for 4 a.m. on July 16, but overnight rain caused a delay. Oppenheimer, Groves, and Bainbridge were loath to postpone. Besides the obvious military implications, a cancellation would require dismantling much of the wiring. Plus, standing on a hill 14 miles distant was a VIP delegation that included Fermi and fellow physicists Edward Teller and Richard Feynman. Also in the small crowd: Klaus Fuchs, a German-born British physicist who was actually a Soviet spy.

The new time for the test was set at 5:30. In his bunker five miles south of ground zero, Oppenheimer oversaw the countdown, which was broadcast through loudspeakers. Everyone was issued either welder’s goggles or pieces of welder’s glass mounted on cardboard. The orders were the same for all: Don’t look directly at the blast. After the initial explosion, you can turn and watch whatever happens next.

Up on their distant hilltops, those who were out of earshot of the countdown were close to giving up their vigil. By 5:30 a.m., some had already turned away and headed back toward their vehicles.

Then the sun came out and touched the Earth.

The oral record of the atomic age’s big bang is remarkably consistent. There was a white flash that seemed brighter than the midday sun. The entire valley, from the nearby scrub to the distant mountain peaks, was illuminated as if at high noon, only in super-sharp contrast.

The light illuminated a rapidly expanding, egg-like structure that started out remarkably symmetrical, but within a second began to roil around the edges. A fiery pillar hurtled upward, then spread out into a bulbous shape, forming the top of the now-iconic mushroom cloud.

A weird purple light illuminated the cloud for a few seconds, the visual evidence of uncontrolled radiation hurtling through the dust. Then the whole thing turned an orangish red, glowing from inside as the temperatures dropped from the unimaginable to the merely dumbfounding.

The ground-level shockwave of Trinity was erratic. Standing outside the south bunker five miles from ground zero, physicist George Kistiakowsky, who’d developed the Gadget’s implosion device, was knocked off his feet. But the ranch house, just two miles from the blast site, suffered only some broken windows and doors. At the VIP site 17 miles away, witnesses reported little more than a strong rumbling and momentary heat on their exposed hands.

The flash was seen in Albuquerque. Up in Gallup, 180 miles northwest, the boom was so loud the local fire department headed for nearby Fort Wingate, thinking a weapons storage facility had exploded.

As predicted, Trinity’s dust cloud drifted northeast with the prevailing winds. Because it rose to 15,000 feet—much higher than anticipated—there was some worry about widespread radioactive fallout. But those concerns would have to wait. For the witnesses assembled at Trinity that morning, it was the sheer destructive power of the explosion that left them speechless. (See the effects of nuclear bomb testing on people in eastern Kazakhstan.)

“A few people laughed, a few people cried, most people were silent,” Oppenheimer later said. “I remembered this line from the Hindu scripture, Bhagavad-Gita: ‘Now, I am become Death, the destroyer of worlds.’”

Site of no return

We are back at the gates. The fire department’s key was as obsolete as Hamilton’s, so my host has taken matters into his own hands, quite literally. As I hold the chain taut, he is wrestling it with a three-foot-long bolt cutter. With a clatter, the chain and lock fall to the desert floor.

“There,” he says triumphantly. “Welcome to Trinity!"

I walk the last few hundred feet, slightly downhill, to the exact spot where the Gadget was detonated. The crater is a broad, surprisingly shallow, plate-like depression. At its greatest depth the hole that Trinity punched into the desert floor measures only about 10 feet. The 100-foot cushion of air under the tower prevented deeper excavation.

Trinity’s pillar and enormous mushroom cloud were comprised largely of desert sand. Also vaporized and blown sky-high were the tower, hundreds of feet of copper cables, and of course the Gadget itself. Of the 13 pounds of nuclear material in the Gadget, it has been estimated that the amount that actually converted to pure energy—resulting in an explosion with the power of 21 kilotons of TNT—measured no more than the mass of a paper clip.

As I approach the 12-foot-tall, black obelisk at Trinity’s hypocenter, I feel like the astronauts walking toward that lunar monolith in Stanley Kubrick’s 2001: A Space Odyssey. This marker was fashioned in the mid-1960s out of blocks mined from a sprawling lava field that spills across White Sands’ eastern perimeter. A large plaque reads “Trinity Site, Where The World’s First Nuclear Device Was Exploded on July 16, 1945.” A second, smaller plaque indicates the site is a National Historic Landmark—a reminder that for years the National Park Service tried to get jurisdiction over the Trinity site.

The desert air is still at White Sands today, but at the foot of this spookily rustic monument, it feels as if the oxygen is being sucked out of the space.

Eckles says he once had a commanding officer who insisted that the Trinity site is second only to Bethlehem—the birthplace of Christ—in world importance. That sounds like crazy talk, but think about it: This is the spot where the modern world was forged in fire. Nearly every major international conflict since 1945, every Cold War nightmare of a holocaust raining from above, every paranoia-fueled overreach by nuke-fearing politicians, every incident in which humankind stepped right up to the line of self-immolation, every child’s suspicion that ducking under a school desk might not be enough, is touched by the scorched tendrils that stretch from Trinity. (Pictures of Hiroshima and Nagasaki show the destructive power of atomic bombs.)

“A lot of people say they’ve waited their whole life to visit here,” says Hamilton as he closes the gate behind us and fashions a temporary chain link from a piece of his keychain. “But in my experience, if you’ve come to Trinity once, you don’t really need to come back.”

That’s because Trinity follows you home.

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