Supermoon is the biggest in 68 years

The biggest and brightest supermoon since 1948 appeared on Monday night, providing a spectacular opportunity for observers and photographers.

As the moon orbits Earth in an oval pattern, it appears to be larger than usual each time it approaches a point close to Earth. This year, there will be a total of six supermoons, including in October, November and December.

According to NASA's website, a full moon won't come this close again until Nov 25, 2034.

The moon arrived at its closest point on Monday at 7:21 pm and became full at 9:52 pm, appearing 14 to 15 percent larger and 20 to 30 percent brighter than usual, attracting amateur astronomers and photographers to observe the phenomenon.

Experts noted that supermoons occur frequently.

"The moon orbits around Earth 13 times a year, so technically we can have 13 supermoons a year," said Chen Xuelei, a researcher at the National Astronomical Observatories of the Chinese Academy of Sciences.

The moon's nearest point to Earth can range from 350,000 to 370,000 kilometers due to orbital variation.

Wang Junjie, another researcher at the National Astronomical Observatories, said the apparent change of the moon's size and brightness might be hard to observe with the naked eye. However, he added that "full moons occurring on the lunar perigee (the closest point to Earth) seem extra big and bright".