Is there life on Mars? Enlarge Image

An image of a mysterious shape on the surface of Mars, taken by Nasa spacecraft Spirit, has reignited the debate about life on the Red Planet.

A magnified version of the picture, posted on the internet, appears to some to show what resembles a human form among a crop of rocks.

While some bloggers have dismissed the image as a trick of light, others say it is evidence of an alien presence.

The image is a recent Nasa posting of the Spirit's landing in 2004.

Perspective

When the robotic rover set down on 24 January 2004, its images disappointed space-watchers hoping for signs of extraterrestrial life.

Now they appear convinced that this image provides the evidence they have been trawling Nasa's photo files for.

The blown-up image seems to resemble a figure striding among the Martian rocks.

The internet has been abuzz with postings offering theories.

Copenhagen's mermaid: Evidence of Martian settlers?

One said it was a garden gnome, another that it was the Virgin Mary.

A third suggested Bigfoot, the hairy bipedal mountain beast that appears in various guises in a number of legends around the world.

But the consensus seemed to be that it bore a striking resemblance to the Little Mermaid statue in the Danish capital, Copenhagen.

Poster "Madurobob" said it was a statue "obviously built by an ancient civilisation that later departed Mars and settled Denmark".

Badastronomy.com tried to apply some perspective: "A man? It's a tiny rock only a few inches high. It's only a few feet from the rover!"