Researchers found likely twins of the giant, erupting star Eta Carinae by comparing infrared images from NASA Spitzer Space Telescope (top) and NASA Hubble Space Telescope (bottom). Astronomers cannot yet explain what caused the titanic eruption of star Eta Carinae in the 1840s. The discovery of likely Eta Carinae "twins" in other galaxies will help scientists better understand this brief phase in the life of a massive star. http://photojournal.jpl.nasa.gov/catalog/PIA20018