As of Friday, Oct. 3, the moon phase is Waxing Gibbous, and according to NASA's Daily Moon Observation, 83% of its surface is illuminated tonight. What are moon phases? From Earth, the moon can look full, partially lit, or even disappear entirely, but we always see the same side. This is how we get full moons, half moons, and moons that appear completely invisible. There are eight main moon phases, and they follow a repeating 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).