In this biography collection, the life and work of some of history's pioneers in the study of astronomy and cosmology are thoroughly explored. This volume provides excellent biographical sketches for trailblazers in the sciences. Articles are devoted to specific scientists, covering the contributions to their field, specifically addressing how their research, discoveries, and inventions impacted human understanding and experience. This historical review includes scientists from around the world and throughout the centuries, with a chapter specifically devoted to the top scientific contributors of the 21st century.