Eta Carinae experienced the Great Eruption in the 19th century - a massive ejection >12Mo. Today we know that Eta Carinae is a massive (>110 Mo) interacting binary enshrouded by dusty winds within an expanding (600 km/s), dusty Homunculus surrounded by an even faster (1000 to 3000 km/s) ionized shell. What led to the Great Eruption? How did/does dust form when carbon and oxygen are greatly depleted? What intermediate molecular species are present? When will the binary system lead to supernovae? The Hubble Space Telescope and Herschel Space Observatory provide new observations that, while increasing knowledge of the system, continue to challenge our understanding of atomic and molecular spectroscopy, interacting massive winds, nucleosynthesis and evolution of massive stars, extreme states of neutral and ionized regions, formation of dust nuclei in massive winds.

Indeed this system is a true astrophysical laboratory!