Helix Nebula: dying Sun, dusty disk, and surviving comets

NASA's Spitzer infrared image captures the Helix nebula, a 700 light-years away planetary nebula—the glowing shell of a sun-like star—with a central white dwarf and a dusty disk likely kicked up by comets that survived the star's death; the finding shows how comets can endure and be redistributed as stars end their lives, and notes that our Sun will form a similar nebula in about five billion years.