FACTBOX: Groundhog Day -- popular non-science

(Reuters) - Following are some facts about Groundhog Day:

* According to lore, if the groundhog emerges from his burrow on February 2 and sees his shadow, he will be frightened back into his hole, presaging another six weeks of winter. A cloudy day -- and no shadow -- means winter will end early.

* The source of the current tradition is unclear but may be based on the European tradition of Candlemas, brought to the United States by German immigrants.

* Since 1887, the groundhog has not seen his shadow only 14 times, compared to 96 times when he saw his shadow. There were no records in nine of the early years.

* "Woodchuck" and "groundhog" are names for the same rodent, the Marmota monax. Related to the squirrel, they eat mainly green plants like dandelion, clover and grasses. They grow to weigh roughly five to nine pounds (2 to 4 kg) in the wild, but can grow much bigger in areas with fewer natural predators.

* Like many animals, groundhogs hibernate during the winter. They often emerge from their underground burrows in early February, when Groundhog Day is marked.

* Punxsutawney Phil weighs 20 pounds (9 kg) and is 22 inches long. Although groundhogs live for six to eight years, legend has it that Phil, who is named after King Philip, has been making predictions for 121 years thanks to a magic elixir that he drinks every summer to get seven more years of life.

* The hype of marking Groundhog Day formed the basis of the 1993 movie of the same name starring comedian Bill Murray.

Sources: Cornell University, Environment Canada, IMDB, www.groundhog.org.