Constellations are groups of stars that appear to form patterns in the sky, though the stars are not physically close together. There are 88 officially recognized constellations. Polaris, also known as the North Star, has been used for navigation for thousands of years as it appears nearly stationary in the sky and always points north. Polaris is actually a triple star system composed of three stars in orbit around each other. Virgo is the second largest constellation and is associated with harvest. Orion is one of the most prominent winter constellations, depicted as a hunter, with his dog Sirius at his feet. According to Greek mythology, Orion boasted that nothing could kill him but was later killed by a scorpion