The spectacular Helix Nebula (NGC 7293) in Aquarius is one of the closest planetary nebulae, lying nearly 700 light-years away. The curling form of the gas is reminiscent of the DNA double helix, leading to its distinctive name. The central star that gave rise to the nebula is plainly visible in backyard telescopes, and astronomers believe the nebula formed about 10,000 years ago.