It’s the Full Moon tonight, and the second this month. This means it is a monthly Blue Moon, which occurs roughly every two or three years.

What is today’s Moon phase?

As of Sunday, May 31, the Moon phase is Full Moon. Tonight, 100% of the moon will be be lit up, according to NASA’s Daily Moon Guide.

Tonight, with just your naked eye, you’ll be able to spot the Mare Vaporum, Copernicus Crater, and the Tycho Crater. If you have binoculars you’ll also be able to catch a glimpse of the Grimaldi Basin, Posidonus Crater, and the Alphonsus Crater. Finally, if you really want to see more, a telescope will help you see the Apollo 14 landing spot, the Linne Crater, and the Caucasus Mountains.

When is the next Full Moon?

The next Full Moon will take place on June 29.

What are Moon phases?

According to NASA, the Moon takes around 29.5 days to orbit Earth, passing through a repeating pattern of eight distinct phases. Although the same side of the Moon always faces Earth, the portion illuminated by the Sun changes as it moves around the planet. This is what creates the different shapes we see in the night sky, from thin crescents to half Moons and the full Moon. Together, these phases form the lunar cycle:

New Moon – The Moon is between Earth and the sun, so the side we see is dark (in other words, it’s invisible to the eye).

Waxing Crescent – A small sliver of light appears on the right side (Northern Hemisphere).

First Quarter – Half of the Moon is lit on the right side. It looks like a half-Moon.

Waxing Gibbous – More than half is lit up, but it’s not quite full yet.

Full Moon – The whole face of the Moon is illuminated and fully visible.

Waning Gibbous – The Moon starts losing light on the right side. (Northern Hemisphere)

Third Quarter (or Last Quarter) – Another half-Moon, but now the left side is lit.

Waning Crescent – A thin sliver of light remains on the left side before going dark again.