Radonić was born in Korčula, Croatia, where he finished primary school and high school. Between 1972 and 2017, he worked in the Technical Museum in Zagreb as a chairman of planetarium with astronautics.
Radonić was born in Korčula, Croatia, where he concluded primary education and secondary education. From 1972 to 2017, he served as the chairman of the planetarium at the Technical Museum in Zagreb with responsibilities related to astronautics.