From floating spoons and coffins to crabs and pyramids, alien hunters are often reporting strange structures in images beamed back from the surface of Mars.

Now, the latest ‘discovery’ seen using high-resolution images of the Martian surface, a mysterious circle of stones have been spotted on top of a raised mound on the planet.

A stone circle that has been compared to Stonehenge has been spotted in images sent back by a spacecraft orbiting the red planet. Dubbed ‘Marshenge’, alien hunters have seized on the images but experts say it could be created by natural processes which cause rocks to be ‘sorted’ in freeze and thaw cycles of permafrost

The stone circle (pictured) was spotted on an apparently raised hummock in images of the Martian surface captured by the HiRise camera on board the Mars Reconnaissance Orbiter

Stonehenge has both captivated and baffled experts for decades and its exact purpose is still unclear. There are many theories that surround it, including from some who believe it was built by aliens

‘The scorn of the sceptics have failed to erode such theories and with the discovery of Marshenge, it builds an even stronger case to suggest astronauts in the past visited our Solar System and had an enduring impact on human history.

‘At present it is a huge leap of the imagination to compare Marshenge with the likes of Stonehenge, for example, we do not know the scale of these objects or what they look like in any detail.

‘Up close they could prove to be random stones cast up by marsquakes – the equivalent of earthquakes – in its distant past.’

A wide range of familiar objects have been spotted in images sent back by spacecraft and rovers on Mars, including a spoon (pictured) apparently floating in mid air and other pieces of cutlery like a chopstick (inset)

Earlier this month, alien hunters say they spotted a mysterious ‘facehugger crab’ on Mars hiding in a cave

Stonehenge on Earth has long been ᴀssociated with supernatural folktales and stories that it had been built by aliens.

Little is known about what the site was actually used for when it was built in around 3,100BC.

Many experts believe it was used for religious ceremonies or to mark the summer solstice.

Others believe it served as a meeting point for the surrounding areas or even for prehistoric people to monitor the heavens.

Earlier this month archaeologists announced the discovery of another line of standing stones around a mile away from Stonehenge that dates back 4,500 years.

The buried stones were found along the south-eastern edge of what later became known as the Durrington Walls ‘superhenge’ – a circular earthworks a third of a mile across.

An unusual rock (left) spotted in Nasa’s archives of images sent back from Mars was claimed to have a striking resemblance to a fossilised iguana (right)

Conspiracy theorists can’t seem to get enough of the shadowy images sent by Nasa’s Mars Curiosity Rover. In one recent ‘discovery’, they claim to have spotted the Star Destroyer from Star Wars

The stone circle on Mars was spotted in images captured by the High Resolution Imaging Science Experiment, or HiRise, camera on board the Mars Reconnaissance Orbiter.

It is the latest in a number of ‘mysterious’ objects seen in images of the surface of Mars.

Recently these have included a coffin-shaped rock, another shaped like a Star Destroyer from the film Star Wars, a crab-like creature shaped like a facehugger from Alien and cutlery.

Nasa rarely comments on these claims but in August a one of its scientists spoke out on the topic to insist that the agency was not trying to hide evidence of alien life from the general public.,

Ashwin Vasavada, who works on the Mars Curiosity Rover mission, said: ‘There is no group that would be happier to see such a thing than the 500 scientists around the world who work on this Curiosty rover.

‘So far we haven’t seen anything that is so obvious that it would be similar to what these claims are.’

Instead he said the sightings were a form of pareidolia, a psychological response that causes the mind to see familiar objects in random places.

In his book Mars, a Warmer Wetter Planet, Jeffrey Kargel, a senior scientist at the department of hydrology at the University of Arizona, said stone circles could appear on Mars as a result of natural geological activity.

He said: ‘Hummocky patterned ground on Mars is probably closely related to permafrost ‘stone circles’ and other forms of sorted terrain on Earth.

‘Sorted stone circles and permafrost hummocks form in extreme polar environments where melting is minimal and this alone should caution us from drawing too definitive conclusions regarding Martian processes.’

Archaeologists recently revealed they had discovered a huge line of giant stones up to 15 ft tall around a mile away from Stonehenge (illustrated). The stones are thought to date back more than 4,500 years