Johannes Kepler was a German astronomer, mathematician, astrologer, natural philosopher and writer on music
Konstantin Tsiolkovsky was a pioneering Russian rocket scientist and cosmonautics theorist, shaping future space exploration.
Antonie Pannekoek was a Dutch astronomer and socialist theorist who made significant contributions to the understanding of the cosmos and the development of Marxist thought.
Christopher Clavius was a German Jesuit mathematician and astronomer who helped develop the Gregorian calendar and mapped the stars with precision.