From Anthrogenica:

Analysis of symbols carved onto stone pillars at Gȍbekli Tepe in southern Turkey – one of the world’s most important archaeological sites – suggests that a swarm of comet fragments hit Earth around 11,000 BC. They ushered in a cold climate that lasted more than 1,000 years.

The stone carvings used in the team's research, found on pillar 43 or '
the Vulture Stone' at Gobekli Tepe in Turkey
[Credit: National Geographic/Getty Images]

Stellar signals

Engineers studied animal carvings made on a pillar – known as the vulture stone – at the site. By interpreting the animals as astronomical symbols, and using software to match their positions to patterns of stars, researchers dated the event to 10,950BC.
Position of the sun and stars in the 10950BC summer solstice
[Credit Martin Sweatman, Stellarium]

The dating from the carvings agrees well with timing derived from an ice core from Greenland, which pinpoints the event – probably resulting from the break-up of a giant comet in the inner solar system – to 10,890BC.

Significant signs

The carvings appear to have remained important to the people of Gobekli Tepe for millennia, suggesting that the event and cold climate that followed likely had a very serious impact.

Researchers from the University of Edinburgh suggest the images were intended as a record of the cataclysmic event, and that a further carving showing a headless man may indicate human disaster and extensive loss of life.

Space observatory
Evidence from the carvings, made on a pillar known as the
Vulture Stone, suggests that a swarm of comet fragments
hit the Earth in around 11000 BC. The different symbols,
said to tell the story, are labelled in the graphic above
[Credit Daily Mail]

Furthermore, symbolism on the pillars indicates that the long-term changes in Earth’s rotational axis was recorded at this time using an early form of writing, and that Gȍbekli Tepe was an observatory for meteors and comets.

The find also supports a theory that Earth is likely to experience periods when comet strikes are more likely, owing to Earth’s orbit intersecting orbiting rings of comet fragments in space.

"It appears Gbekli Tepe was, among other things, an observatory for monitoring the night sky. One of its pillars seems to have served as a memorial to this devastating event – probably the worst day in history since the end of the ice age”, says lead researcher Martin Sweatman, from the University of Edinburgh’s School of Engineering.

http://www.dailymail.co.uk/sciencete...years-ago.html