It is known that some stars in the sky end their life in the brilliant explosion of a supernova. The mechanism of the supernova explosion, however, has long been a mystery in astronomy. I’ve been working on observations of supernovae using large, modern telescopes. As a result, complex three-dimensional geometry, surely a key to understanding the explosion mechanism, has become apparent. I’m also interested in numerical simulations and observations of supernovae in the distant, early universe.