Mendelevium

Mendelevium is a synthetic, highly radioactive element primarily produced through human-made nuclear reactions, and it is virtually non-existent in natural astronomical settings. As a product of artificial creation, mendelevium is exceptionally rare beyond Earth, resulting in negligible astronomical significance. Its isotopes possess very short half-lives, often lasting from days to years, which further contributes to its absence in celestial bodies or cosmic environments. Mendelevium's synthetic nature confines its presence primarily to controlled laboratory conditions, such as in nuclear reactors or as a byproduct of nuclear processes.