In the spring of 1955, as the Cold War intensified and the arms race between the United States and the Soviet Union escalated at a shocking pace, America — as it had many times before — detonated an atomic weapon in the Nevada desert. The test was not especially noteworthy. The weapon's "yield" was not dramatically larger or smaller than that of previous A-bombs; the brighter-than-the-sun flash of light, the mushroom cloud and the staggering power unleashed by the weapon were all byproducts familiar to anyone who had either witnessed or paid attention to coverage of earlier tests.
And yet today, six decades later, at a time when the prospect of nuclear tests by "rogue states" like North Korea and Iran is once again making headlines and driving international negotiations and debate, the very banality of one long-forgotten atomic test in 1955 feels somehow more chilling than other more memorable or era-defining episodes from the Cold War. After all, whether conducted in the name of deterrence, defense or pure scientific research, the May 1955 blast (the results of which are pictured in this gallery) was in a very real sense routine.
This is not to suggest that the scientists, engineers and other professionals involved at Yucca Flat were somehow cavalier about detonating atomic weapons. But it's worth remembering that, in the first half of 1955, the U.S. conducted more than a dozen nuclear test explosions in Nevada alone. After a while, the mushroom clouds from these tests, visible from Las Vegas 60 miles away, had become tourist draws. One needn't be a pacifist, an anti-nuclear crusader or a modern-day Luddite to shudder at the thought of nuclear explosion after nuclear explosion ripping through the desert air of the American southwest.
Here, LIFE.com presents pictures — most of which never ran in LIFE magazine — made in the Nevada desert by photographer Loomis Dean shortly after a 1955 atomic bomb test. These are not "political" pictures. They are eerily beautiful, unsettling photographs made at the height of the Cold War, when the destructive power of the detonation was jaw-droppingly huge — but positively miniscule compared to today's truly terrifying thermonuclear weapons. As LIFE told its readers in its May 16, 1955, issue (in which some of these photos appeared):
A day after the 44th nuclear test explosion in the U.S. rent the still Nevada air, observers cautiously inspected department store mannequins which were poised disheveled but still haughty on the sand sand in the homes of Yucca Flat. The figures were residents of an entire million-dollar village built to test the effects of an atomic blast on everything from houses to clothes to canned soup.
The condition of the figures — one charred, another only scorched, another almost untouched — showed that the blast, equivalent to 35,00 tons of TNT, was discriminating in its effects. As one phase of the atomic test, the village and figures help guide civil defense planning — and make clear that even amid atomic holocaust careful planning could save lives.
There is, in such words and in such sentiments, an almost unrecognizable optimism — it's tempting to say, an innocence — that is no longer available to us when it comes to honest discussions of, as LIFE put it, "atomic holocaust." With conversations about nuclear tests (both theoretical and real) so very much in the news these days, these pictures from more than half a century ago serve as a quiet reminder of just how horrific and deranged the very notion of nuclear warfare really is.
Ben Cosgrove is the Editor of LIFE.com
Liz Ronk, who edited this gallery, is the Photo Editor for LIFE.com. Follow her on Twitter at @LizabethRonk.