Héctor Germán Oesterheld (born July 23, 1919; disappeared and presumed dead 1977) was an Argentinean journalist and comics writer. Considered the most important Latin American comics writer, Oesterheld is known for creating characters including Sargent Kirk, Bull Rocket, Ernie Pike, Sherlock Time and Mort Cinder, but without doubt he is best known as the creator of The Eternonaut. Oesterheld worked with the best artists and illustrators of his time, including Alberto Breccia and Francisco Solano Lopez. Oesterheld's work took on increasingly political tones in the 1960s and 1970s, and he, along with his four daughters (two of whom were pregnant at the time), were arrested by the Argentinean military government. There is no information about what happened to them, but they are all presumed dead. The Eternonaut was published in Hora Cero, edited by Oesterheld, in weekly installments beginning in 1957. It is widely considered one of the most important Latin American texts in both science fiction and comics.