I have not seen the photo you referenced, but by your description, the 'symbol' sounds also like a 'goddess' design. The crescent moon, in an upward "smile" design is usually worn on the forehead, like a crown in goddess worship. 

http://img329.imageshack.us/img329/3654/selene2nv1.jpg

http://static.artfire.com/admin/product_images/thumbs/--90000--87375_product_195721699_thumb_medium.jpg

Not saying that has anything to do with any 'signs', but just wanted to let you know that we are not the only ones 'looking up'. The study/worship of the night sky is especially important to wiccan/pagan people. Anything that affects the moon would have meaning for them...with upward being a positive thing.

Blessings~

Suzi