Maia Callisto with Zeus. Wronged by the love affair, Zeus' wife Hera in a jealous rage had transformed Callisto into a bear. Arcas is the eponym of Arcadia, where Maia was born. The story of Callisto and Arcas, like that of the Pleiades, is an "aition" for a stellar formation, the constellations Ursa Major and Ursa Minor, the Great and Little Bear. Her name is related to μαῖα ("maia"), an honorific term for older women related to μήτηρ ("mētēr") 'mother'. "Maia" also means "midwife" in Greek. In ancient Roman religion and myth, Maia embodied the concept of growth, as her name
Ursa (Finland) include advancing amateur astronomy and astronomical education. They have also published a magazine "Tähdet ja avaruus" since 1971. Anyone can join Ursa for an annual fee. The organization has thirteen sections specialized in different aspects of amateur astronomy (and meteorology): In addition, Ursa has two loosely organized hobby groups: Ursa (Finland) Ursa Astronomical Association () is the largest astronomical association in Finland. Ursa was founded on 2 November 1921. Founding members include a renowned Finnish astronomer Yrjö Väisälä. In 1926 Ursa established the Ursa Observatory in Kaivopuisto district of Helsinki. In 2007 the Tähtikallio Observatory & Education Center was established