Tsiolkovskiy

Tsiolkovskiy is a massive impact crater located on the far side of the Moon, meaning it is never visible from Earth. It sits in the southern hemisphere of the lunar far side. The Soviet Luna 3 probe famously photographed this crater in 1959, providing humanity with its first glimpse of the Moon's hidden side.

The crater floor is filled with dark basaltic lava, which erupted into the crater basin long after the initial impact occurred. This mare-like material stands in stark contrast to the brighter, older highlands surrounding the crater. This late-stage volcanic activity is relatively rare for far-side lunar geography, making Tsiolkovskiy a focal point for geological study.

The crater is named after Konstantin Tsiolkovsky, a Russian schoolteacher and pioneer of astronautic theory. He is widely considered the father of human spaceflight for his late 19th-century theoretical work on rocket equations. Naming a massive lunar crater after him honors his visionary concepts of multi-stage rockets and space elevators.

The crater features a massive diameter of approximately 185 kilometers, making it one of the largest craters on the Moon. The interior of the crater is isolated from the surrounding terrain by a massive inner wall that rises up to 3,000 meters. The central peak, formed by the rebound of the crust after the impact, rises sharply from the dark lava floor.