The dust storm that left the Opportunity rover out of commission is now classed as 'planet-encircling'.
The construction of the world-famous stone circle may have been all about bringing people together.
A crane operator working on a construction site has recorded footage of a 360-degree rainbow.
The space agency has released a new image of a peculiar circle on Mars - but what exactly is it ?
Ecologists believe that they may have finally solved the mystery behind Namibia's mysterious circles.
A huge alligator was filmed by tourists at the Circle B Bar Reserve in Polk County, Florida this week.
Thousands were left perplexed by the high-altitude aircraft which circled for about an hour on Wednesday.
These mysterious circular, grass-ringed patches are still leaving scientists scratching their heads.
Archaeologists have unearthed evidence of a huge circle of timber posts just two miles from Stonehenge.
Professor Richard Taylor has called for a renewed effort to understand how crop circles are formed.
Strange circular, grass-ringed patches have been discovered over hundreds of square kilometers.
A huge flightless bird called Gastornis is thought to have once roamed what is now the Arctic Circle.
Phobos, one of the two small moons of Mars, could eventually break apart and encircle the planet.
A former RAF engineer claims that MI5 hired crop circle hoaxers to discredit the UFO phenomenon.
Archaeologists have uncovered a hidden stone monument situated just two miles from Stonehenge.
New aerial footage has been released showing an intricate pattern of circles in a field in Russia.
A previously undiscovered stone circle has been unearthed by archaeologists in southern England.
A woman who had been filming the eruption also recorded an object that had appeared in the sky nearby.
A new theory has proposed that the prehistoric stone circle may have supported a large wooden altar.
The mysterious patterns were once believed to be secret codes designed to guide German bombers.