The first supermoon of the year is approaching. Here's what to know

The moon will appear slightly larger and brighter Monday night during what's known as a supermoon.

October's supermoon is the first of three this year. It happens when a full moon is closer to Earth in its orbit. That makes the moon look up to 14% bigger and 30% brighter than the faintest moon of the year, according to NASA. The subtle difference happens a few times a year, sometimes coinciding with other astronomical events such as lunar eclipses.

The moon will appear slightly larger and brighter on Monday. It's the first of three supermoons this year.

"It's not really very unusual," said Derrick Pitts, chief astronomer with the Franklin Institute in Philadelphia.

Everyone in the world can see a supermoon without special equipment if clear skies permit. But the difference can be tough