It was once one of the brightest stars in the heavens, easily visible to mariners navigating by the southern sky in the mid-1840s. But the star Eta Carinae quickly faded into obscurity after its brief outburst. Now, over a century and a half later, NASA space observatories (probing from infrared light through X-rays) have enabled astronomers and artists to assemble a three-dimensional model of the Homunculus Nebula and accompanying clouds of dust and gas enshrouding the petulant star. More than just an eye-catching visualization, the story of the 1843 Great Eruption and the history of the expelled nebula is designed to enrich astronomical learning, a key goal of NASA's Universe of Learning.