NASA / JPL-Caltech / SSC
Layers of gas and dust show up clearly in this color-coded composite picture of the Helix Nebula. Ultraviolet wavelengths, as seen by the GALEX probe, are shown in blue. Infrared wavelengths, as seen by NASA's Spitzer Space Telescope, are presented in red, yellow and green. The nebula appears magenta in the center, where the two sets of data overlap. A portion of the extended field beyond the nebula is from NASA's Wide-field Infrared Survey Explorer.
More than 600 light-years away, the Helix Nebula stares at us like the Eye of God — or like the Eye of Sauron in the "Lord of the Rings" film saga. This new picture combines readings from two space telescopes to fill out our picture of the eye.
The pinkish light you see pouring from the center of the image doesn't show up in visible-light images — but in this view, it's an essential part of the staring-eye effect. That comes from a combination of the infrared emissions spotted by NASA's Spitzer Space Telescope; and ultraviolet emissions that were detected by the Galaxy Evolution Explorer, or GALEX, which was launched by NASA and is now being lent to Caltech for continuing research.
Here's the story behind the eye: The Helix, also known as NGC 7293, was created when a dying sunlike star started blasting away its outer layers of gas and dust. Radiation has cleared away the area around the star, which is now a dense white dwarf, but the colorful gaseous shells of gas that were thrown off continue to spread outward. GALEX traces the ultraviolet glow of those shells in shades of deep blue. Meanwhile, Spitzer sees the infrared emissions from the nebula's gas and dust. The different infrared wavelengths are shown in red, yellow and green.
You can compare the ultraviolet-plus-infrared view with this infrared view from Spitzer, or with this one from the European Southern Observatory's VISTA telescope, or with this video that takes you on a 3-D tour through the Hubble Space Telescope's visible-light image. (As a bonus, you get a lesson about the Helix Nebula and other planetary nebulae along with the pretty pictures.)
Scientists believe the blast that caused the Helix Nebula is the same fate that awaits our own sun in 5 billion years or so. We won't have to worry about that for a while, but the "Eye of God" serves as a reminder that even stars sometimes go out with a blaze of glory.
More blazes of glory:
- New clues to the most amazing shapes in space
- Team aims to score a cosmic goal
- The inside story of a dying star
- Stages of a star's death
Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.