New Delhi: Get ready for an exceptional celestial treat as the biggest and brightest full moon of the year will be seen in the night sky on Saturday.

“The 'supermoon' will be closest to the Earth in 18 years on Saturday and will appear to be the biggest and brightest of 2011, Director of Science Popularisation Association of Communicators and Educators (SPACE) C B Devgun said.

“Saturday's full moon will be around 10 per cent bigger and 30 per cent brighter as compared to other full moons during the year,” he added.

The term 'Supermoon' was first coined by Astrologer Richard Nolle in 1979. According to him, it is a situation when the moon is slightly closer to the Earth in its orbit than average, which is 90 per cent or more of its closest orbit, and the moon is a full or new moon.

On Saturday, the moon will be only 3,56,577 kms away from the Earth, the closest. Earlier, there were supermoons in 1955, 1974, 1992 and 2005.

At the closest, our natural satellite moon lies roughly 3,56,630 kilometres from the Earth compared to its average distance of 3,84,800 km from the planet.

The full moon will be at its best at around 3:30 AM, R C Kapoor, a retired professor of Indian Institute of Astrophysics said.