People around the world are preparing for a rare astronomical spectacle - a supermoon. The largest and brightest full moon in nearly seventy years will light up the night sky this evening.

The "supermoon" is seen over Beijing, capital of China, Nov. 14, 2016. The supermoon is the closest full moon to the earth in 69 years, according to NASA. [Xinhua]

The spectacle refers to an astronomical phenomenon in which the full or new moon looks bigger and brighter than usual, as its orbit brings it closer to the Earth.

Monday night's supermoon is the biggest since 1948. Astronomers say that around every 14th full moon is a supermoon. The next time the moon comes this close to Earth will be in 2034.