ToplineThe moon is expected to reach its closest point to Earth tonight, resulting in the largest supermoon this year, according to experts, an unofficial astronomical phenomenon that occurs up to four times annually.

October's supermoon, known as the "Hunter's Moon," will be the biggest and brightest full moon of the year. Why it matters: The third of this year's four consecutive supermoons arrives during an active month of skywatching between rare northern lights sightings and the once-in-a-lifetime comet.

This week's full moon is called the Hunter's Moon. It's also a supermoon, which is expected to be the brightest one of the year so far.