Trinity Site, New Mexico - A National Historic Landmark

Ground Zero

On July 16, 1945, the world was ushered into the atomic age with a blinding flash. At 5:30 a.m. that day, the first atomic bomb was detonated at a site called Trinity, about 50 miles southeast of Socorro, New Mexico. All life on earth has been touched by the event which took place here.

In the panorama photo, above, Ground Zero is enclosed by an oval fence. It encloses the point of detonation marked by the obelisk (circled, and in photos, left and right) and the crater created by the fireball which was about 100 yards across. The shallow radioactive crater was cleaned up and filled in 1952. The low shed beyond the pickup truck preserves a small section of the crater.

At right, photos then and now. The left photo was taken 28 hours after the detonation. The scale at lower left is 100 yards. The crater is circled. The right photo is the contemporary site. The circular fence encloses the blast area; the oval fence, Ground Zero.

The Semi-Annual Open House

Since 1953, the White Sands Missile Range has conducted open houses at Trinity Site which was designated a National Historic Landmark in 1975. On the first Saturdays of April and October, visitors may tour Ground Zero (above) and the historic McDonald Ranch where the Bomb was assembled. And thousands of people show up to visit Trinity.

(Photos, left. The Bomb was detonated atop a 100 foot tower. Far left, a little bit of the tower's footing still remains. There was originally more exposed steel pipe and rebar but it was cut away. The footing was not completely vaporized like the rest of the tower because it was packed in concrete.)

Surprisingly, the mood at the open house is quite festive, almost carnival-like. Off-duty military personnel are selling hamburgs, hot dogs, and hot drinks (luckily, because it's a cold, bitter day). Vendors hawk "mushroom cloud" t-shirts and other souvenirs. Someone else is selling books. One might have expected a somber mood here. On the other hand, perhaps we feel pretty good about surviving it all. The decades of having the threat of nuclear annihilation hanging over our heads have faded. There clearly wasn't much of a fear factor in evidence today. And the horror of dropping one of these devices on people, even in a righteous cause, is too many decades removed for most people to closely contemplate.

In the photo above right, visitors contemplate Ground Zero with the Oscura Mountains in the background to the east. One of the tower footings is to the left of the man in the blue jacket. In the photo above left, the press is shown contemplating Ground Zero for the first time on September 11, 1945. Dr. Robert Oppenheimer (center, in the white hat), scientific director of the Manhattan Project (to develop the bomb), explains things. Next to him is General Leslie Groves (the portly soldier), the project's military director. Note the protective footwear being worn. The surface of the crater, which looks like cracked mud is actually a unique substance called trinitite. The heat of the fireball fused the plentiful silicon in the desert sand creating this glass-like substance. The trinitite was radioactive, and most of it was scraped away during the site cleanup in 1952.

Is the site still radioactive today? Yes, slightly. There is an emission of 1/2 to 1 millirem per hour in the crater area. This compares with 3 to 5 mrem for a typical coast to coast jet flight or 22 mrem for a chest xray.

At right, the Trinity blast about ten seconds after detonation. The column of smoke (the mushroom's "stem") was about 200 yards across at this point. At left, the actual bomb being readied at the top of the tower. This plutonium bomb was being tested because the detonation scheme required to compress a ball of plutonium into a critical mass was quite complex. The uranium bomb dropped on Hiroshima was relatively simplistic and did not require advance testing.

At right is an early casing for a plutonium atomic bomb. This was very similar to the Fat Man bomb dropped on Nagasaki on August 9, 1945.

At left, a display case of trinitite near Ground Zero. Behind it is a Geiger counter. The old style clock to the right was part of the interpretor's demonstration. She was showing that old clocks and meters which had radium coatings on their dials generate greater readings than the trinitite.

The photos (below right) show the shed which preserves the section of crater that was not filled in. The crater was actually shallow, only about 2 to 3 feet deep. It was covered primarily to make the site safe for visitation. At far right is a closeup through the open window. The small piles of grayish rocks in the center are all that's left of the trinitite. Otherwise, it's just sand.

The open house also includes a bus ride to the historic McDonald ranch house two miles south of Ground Zero. The ranch was abandoned in 1942 when the area became a military reservation. On July 12-13, 1945, the house was used as the assembly point for the Bomb. The house survived the blast with only broken windows. The adjacent barn did not fare as well, suffering major damage. At the time of detonation, the primary scientists were in a bunker 10,000 yards south of Ground Zero.

The photos below: left, the rear of the ranch house; right, the front (which is seen in the famous photo where the plutonium is being unloaded from a car); and center, the master bedroom used as the "clean" room to assemble the core of the bomb. The sign on the door reads, "Please use other doors, keep this room clean."

In 1945, the physicist, Leo Szilard, who originally conceived the idea of a nuclear chain reaction, led a faction of scientists which wanted to petition President Truman not to use the bomb. His reasoning was that the result would be a nuclear arms race with the Soviets, that a hydrogen bomb would soon be developed, and that World War III and total annihilation would be inevitable. (Szilard was despised by General Groves and those who wished to deploy the weapon. They ulitmately coerced Oppenheimer into surpressing the petition to Truman.)

In the world of 1945, the concept of total war and the killing of millions was being practiced in real life. What Szilard underestimated was the powerful human survival instinct. When the rival powers attained the ability to annihilate each other and the world, they were able to rise above the politics of confrontation enough to say no to nuclear war, but just barely. (Remember 1962.) Sadly, in the post-2001 world, we are again worrying about nuclear weapons and other assorted "weapons of mass destruction", real or imagined. Not much of a respite.