An astronomical sighting is the observation of a celestial object or phenomenon. Common astronomical sightings include meteors, moons, Oort clouds, novae, and novae. Meteors are small pieces of rock or metal that enter Earth's atmosphere and burn up, creating a streak of light in the sky. The MOON is Earth's only natural satellite and can be seen in the night sky. Oort clouds are vast collections of icy objects located at the edge of the Solar System. Novae are stars that suddenly increase in brightness due to a sudden release of energy. Novae are often mistaken for supernovae, which are much brighter and occur when a star explodes. Finally, YETI is a term used to describe an unidentified creature that is said to inhabit the Himalayan region.