WASHINGTON - The explosion of a star halfway across the universe was so huge it set a record for the most distant object that could be seen on Earth by the naked eye. The aging star, in a previously unknown galaxy, exploded in a gamma ray burst 7.5 billion light years away, its light finally reaching Earth early Wednesday. The gamma rays were detected by NASA's Swift satellite at 2:12 a.m. "We'd never seen one before so bright and at such a distance," NASA's Neil Gehrels said. It was bright enough to be seen with the naked eye. However, NASA...