Greek mythology in popular culture elements tantalum and niobium are always found together in nature, and have been named after the King Tantalus and his daughter Niobe. The element promethium also draws its name from Greek mythology, as does titanium, which was named after the titans who in mythology were locked away far underground, which reflected the difficulty of extracting titanium from ore. The U.S. Apollo Space Program to take astronauts to the moon, was named after Apollo, based the god's ability as an archer to hit his target and being the god of light and knowledge. Oceanographer Jacques-Yves Cousteau named his research ship, a
Sister-wife of Njörðr Sister-wife of Njörðr In Norse mythology, the sister-wife of Njörðr is the unnamed wife and sister of the god Njörðr, with whom he is described as having had the (likewise incestuous) twin children Freyr and Freyja. This shadowy goddess is attested in the "Poetic Edda" poem "Lokasenna", recorded in the 13th century by an unknown source, and the "Heimskringla" book "Ynglinga saga", a euhemerized account of the Norse gods composed by Snorri Sturluson also in the 13th century but based on earlier traditional material. The figure receives no further mention in Old Norse texts. The situation is further complicated in