Kees de Jager is a Dutch astrophysicist known for his contributions to the study of solar physics and space weather. He was born on March 14, 1921, in the Netherlands and has had a long and distinguished career in science, focusing on the behavior of the Sun and its impact on the Earth. Throughout his career, de Jager has published numerous papers and has been involved in various international research projects. He is particularly recognized for his work on solar cycles and their effects on satellites and communication systems. His research has helped improve our understanding of the solar wind and its influence on the Earth's atmosphere.