It's the start of a new phase in the lunar cycle tonight, and for now, that means the moon will be getting brighter each night.
The lunar cycle is a series of eight phases of the moon. NASA explains that these phases occur as the Sun illuminates varying portions of the moon while it moves around our planet. The cycle in general lasts around 29.5 days.
Keep reading to see what you can see when you look up tonight, Sept. 30.
What is today’s moon phase?
As of Tuesday, Sept. 30, the moon phase is Waxing Gibbous, and according to NASA's Daily Moon Observation, 56% of its surface is illuminated tonight.
If you enjoy a bit of moon gazing, there's a lot for you to see tonight. You won't need any visual aids to see the Mare Crisium, the Mare Vaporum, and the Mare Fecunditatis. With binoculars, you can add the Archimedes Crater, Endymion Crater, and the Mare Nectaris to your lineup.
If you have a telescope, you can also see the Linne Crater, Rima Hyginus, and the Rupes Altai.
When is the next full moon?
The next full moon will be on Oct. 7. The last full moon was on Sept. 7.
What are moon phases?
According to NASA, the moon’s phases are part of its 29.5-day orbit around Earth. As the moon moves, the angles between the Sun, Moon, and Earth shift, creating the changing phases we see. From our perspective, the moon sometimes appears full, sometimes seems to vanish completely, but we always see the same side. What changes is how much sunlight is reflecting off its surface, depending on its position in 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.
