Full moon – when the moon is most opposite the sun for this month – falls on May 18, 2019, at 21:11 UTC. As the 3rd of 4 full moons in a season, it’ll be called a Blue Moon.

The 1st quarter moon comes on May 12 at 1:12 UTC. At European and American time zones, you’ll find it high up at sunset on May 10 and 11. It appears nearly or completely half-illuminated, like half a pie.

You can’t see a new moon; it’s between the Earth and sun and crosses the sky with the sun throughout the day. Will you see the returning young crescent moon in the west after sunset May 5? Maybe, with effort. The young moon will sweep past Mars around May 6 to 8.

A waning gibbous moon is a moon between full and last quarter. Watch for this moon phase from late night through early morning.

Many people report seeing earthshine on a waxing crescent moon. That’s when the darkened portion of the crescent glows dimly with light reflected from Earth.

A waxing gibbous moon appears more than half lighted, but less than full. It rises before sundown and sets somewhere between midnight and dawn.

A waning crescent moon is up in the east before sunrise. It’s waning toward new moon, when the moon will be between the Earth and sun.

Half the moon always faces us. And half the moon is always lit by the sun. But, in the language of astronomers, there are no ‘half moons.’