Our sun and billions of stars just like it are headed for a strange, cold destiny. New research suggests that long after our roiling, boiling life-giving star runs out of fuel it will slowly form a cold, dead, super-dense crystal sphere about the size of the Earth that will linger like a translucent tombstone for close to eternity. “In tens of billions of years from now the universe will be made largely of dense crystal spheres,” said Pier-Emmanuel Tremblay, an astrophysicist at the University of Warwick in Coventry, England, who led the work published this week in Nature.