The moon looks almost full tonight, but it's not quite there. We've even got a few more days before we hit that part of the lunar cycle.
The lunar cycle is a series of eight unique phases of the moon's visibility. The whole cycle takes about 29.5 days, according to NASA, and these different phases happen as the Sun lights up different parts of the moon whilst it orbits Earth.
So, what's happening with the moon tonight, Aug. 5?
What is today’s moon phase?
As of Tuesday, Aug. 5, the moon phase is Waxing Gibbous. According to NASA's Daily Moon Observation, the moon will be 85% lit up tonight, the 12th day of the lunar cycle.
With each night we progress through the lunar cycle, there is more visibility for us on Earth. With your unaided eye, you'll be able to spot many things tonight, but most notably the Mare Vaporum, the Mare Tranquillitatis, and the Tycho Crater.
Pull out the binoculars to add the Mare Humorum, the Apennine Mountains, and the Archimedes Crater, which, according to NASA, is about 3/4 the size of Washington, DC. And with a telescope, enjoy glimpses of the Schiller Crater, the Descartes Highlands, and the Gruithuisen Domes, something NASA calls a "geologic mystery." One mile tall, these volcanic mountains are steeper than normal lunar volcanoes, despite missing water and plate tectonics that help volcanoes form on Earth.
When is the next full moon?
The next full moon will be on August 9. The last full moon was on July 10.
What are moon phases?
According to NASA, moon phases are caused by the 29.5-day cycle of the moon’s orbit, which changes the angles between the Sun, Moon, and Earth. Moon phases are how the moon looks from Earth as it goes around us. We always see the same side of the moon, but how much of it is lit up by the Sun changes depending on where it is in its orbit. 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).
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.
Last Quarter (or Third 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.
