Giovanni Battista Hodierna was a 17th-century Italian astronomer and naturalist, born in 1597 in Sicily. He is best known for his work in observational astronomy and for his contributions to the study of celestial bodies. Hodierna created detailed star catalogs and was one of the early proponents of using telescopes for astronomical observations. In addition to his astronomical work, Hodierna was also interested in natural history and wrote about various scientific topics. His most notable publication, "De Systemate Orbis," discussed the structure of the universe and included ideas that were ahead of his time, influencing later astronomers and scientists.