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.
Here, in this gallery, LIFE.com presents rare and (mostly) unpublished pictures made in the Nevada desert by photographer Loomis Dean shortly after a 1955 atomic bomb test.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.
Click the pic to take a closer look.