Astronomers spot the same supernova three times — and predict a fourth sighting in 16 years. An enormous amount of gravity from a cluster of distant galaxies causes space to curve so much that light from them is bent and emanated our way from numerous directions. This 'gravitational lensing' effect has allowed astronomers to observe the same exploding star in three different places in the heavens. They predict that a fourth image of the same explosion will appear in the sky by 2037. The study provides a unique opportunity to explore not just the supernova itself, but the expansion of our universe. Source 7o.