mushroom cloud

A mushroom cloud is a distinctive, mushroom-shaped formation that results from a massive release of heat and energy. While most famously associated with thermonuclear explosions, such clouds can also be formed by other powerful heat sources, like volcanic eruptions or large explosions such as the 2020 Beirut explosion.

The formation begins with a rapidly ascending fireball of heat and energy, which creates a vacuum behind it. This vacuum is then filled with smoke and debris, forming the cloud's central column. As the fireball rises and encounters cooler, denser air, its ascent slows, and the surrounding air flattens the top, creating the characteristic mushroom shape. These clouds can linger for about an hour before dispersing due to wind and air currents. The term "mushroom cloud" was first used around 1909.12