In JRR Tolkien's Lord of the Rings trilogy, the malevolent title character Sauron is an evil force represented by a single fiery eye. A ring of dust around the bright star Fomalhaut looks uncannily like the Great Eye of Sauron in this image taken by the Hubble Space Telescope a few years ago. The image confirms that Fomalhaut's ring is curiously offset with respect to the star, suggesting that the gravity of one or more unseen planets is dragging the ring askew. (Image: NASA, ESA, Kalas/Graham/UCB, Clampin/NASA/GSFC)

A giant, spectral "eel" appears to be chasing after a spiral galaxy in this image from the Victor M Blanco telescope in Chile. The eel is actually a type of small, isolated cloud of gas and dust called a cometary globule because of its resemblance to a comet. Called CG4, it lies about 1300 light years from Earth towards the constellation Puppis, at the stern of the ship of the Argonauts. The eel appears on the verge of devouring a spiral galaxy called ESO 257-19. Fortunately, that galaxy is safely out of reach, actually lying more than 100 million light years farther away than CG4. (Image: TA Rector/T Abbott/U Alaska/NOAO/AURA/NSF)

A ghostly visage is haunting the galaxy in the form of the Skull Nebula, which lies 1600 light years from Earth in the constellation Cetus, the Sea Monster. It is one of about 1600 known planetary nebula, which form when stars up to eight times the mass of the Sun begin to die. They bloat into red giants before shedding as much as half their mass in shells of gas and dust. Left behind are dense stellar corpses called white dwarfs. The white dwarf in this nebula is speeding through space at 80 km/s. Gas sloughed off the star in the direction of its movement (up) slams into surrounding interstellar gas and compresses, while gas expelled in its wake expands freely, explaining why the skull's top half is more defined than its gaping mouth. (Image: Gemini South GMOS/T Rector/U Alaska) Advertisement

Forget 'canals' on Mars - when the Viking 1 probe returned this image of a face on the Red Planet in 1976, some speculated that it must have been built by aliens. More recent images reveal it to be merely an eroded hill, but there are plenty of other suspicious-looking features on Mars to keep conspiracy theorists busy for a long time to come. (Image: NASA)

A monstrous jellyfish larger than the Milky Way floats 400 million light years away. The Cartwheel galaxy's concentric rings of star formation were probably triggered by a collision with a smaller galaxy, possibly one of the ones in the bottom-left of this multi-wavelength image. (Image: GALEX/Chandra/Hubble/Spitzer)

A mammoth network of gas filaments inside the galaxy NGC 1275 resembles the Flying Spaghetti Monster. Until recently, it was not clear what prevented the delicate filaments from being destroyed by competing gravitational forces, but Hubble Space Telescope images suggest they are supported by magnetic fields generated near the galaxy's central black hole. (Image: Fabian et al./NASA)

A dark figure seems to emerge from the fog in this image of a gas and dust nebula called NGC 1999. A bright young star called V380 Orionis (upper left) illuminates the nebula - except for where a cold cloud of gas and dust is so dense that it blocks all light behind it. Stars may be condensing inside this dark cloud, called a Bok globule. (Image: NASA/Hubble Heritage Team/STScI)

A giant black widow is lurking in the Milky Way, spawning young and zapping its surroundings with intense radiation. Hanging just above the galactic plane, the Black Widow Nebula is a cloud of dust, gas and stars about 10,000 light years from Earth. NASA's Spitzer Space Telescope captured wispy streams of dust, flowing like spider's legs from the centre of the nebula, where massive young stars are forming. These enfants terribles are actually spewing out radiation and particles that "are basically destroying their natal material", said Ed Churchwell, an astronomer at the University of Wisconsin in Madison, US, who led the observations. (Image: NASA/JPL-Caltech/E Churchwell/GLIMPSE)

Saturn's moon Mimas looks for all the world like the Death Star - the planet-destroying space station from the movie Star Wars - in this Cassini image taken in 2005. The giant crater at the centre of the image, called Herschel, was probably gouged out by an enormous asteroid impact. If the asteroid had been any bigger or had been moving much faster, it probably would have split the moon in two. (Image: NASA/JPL/Space Science Institute)