Comets collide in the Eye of God

The Eye of God stares back at us from deep in the universe in this spectacular picture from a space telescope. The eerie image, shot with Nasa’s Spitzer instrument, is really the shimmering remains of a dead star that has thrown its gas out into space.

Spitzer image of the Helix nebulaThe heat-seeking telescope reveals the star itself like a red pupil at the centre of the eye.

And it has discovered a surrounding cloud of dust that astronomers believe is caused by comets colliding as they continue to circle their lost sun.

The cloud of gas and dust was dubbed the Eye of God after another space telescope, Hubble, photographed it.

Lead scientist Dr Kate Su, of the University of Arizona, said: “We were surprised to see so much dust around this star. The dust must be coming from comets that survived the death of their sun.”

The cloud is a type known as a planetary nebula, although it has nothing to do with the planets. It is usually known as the Helix and can be seen as a dim ring in stargazers’ backyard telescopes. It lies around 700 light years away in the constellation of Aquarius and is so big that light takes two and a half years to travel from one side to the other.

The star that formed the Eye is believed to have been much like our own sun before it died and threw off its outer layers. Our own solar system will meet a similar fate five billion years in the future.

The expanding shell of gas that forms the white of the Eye is shining like a fluorescent striplight as it is heated by the dead star’s core. Experts say that the spectacle will not last long on the cosmic timescale and will fade away in around 10,000 years.

Previous spectacular images from Spitzer have included the dust wave threatening the Pillars of Creation and the swirling stellar nursery that is the Orion Nebula.

The dust cloud discovery will be announced in next months’s issue of the Astrophysical Journal. Photo: NASA/JPL-Caltech/University of Arizona.