Einsteinium
Einsteinium is a synthetic, highly radioactive element primarily produced through human-made nuclear reactions and is not naturally abundant in the universe. Its artificial creation and extreme rarity beyond Earth result in minimal astronomical significance. With isotopes characterized by very short half-lives, often ranging from days to years, einsteinium is exceptionally scarce in celestial bodies or cosmic environments. Its synthetic nature confines its presence primarily to laboratory settings, such as in nuclear reactors or as a byproduct of nuclear processes.