It’s a new lunar phase tonight, First Quarter, which means we’re seeing around half of the moon tonight.
The moon goes through a cycle of eight distinct phases, known as the lunar phases. NASA explains that these phases occur as the Sun illuminates varying portions of the moon while it moves around our planet.
Keep reading to see what you can see when you look up tonight, Sept. 29.
What is today’s moon phase?
As of Monday, Sept. 29, the moon phase is First Quarter, and according to NASA’s Daily Moon Observation, 46% of its surface is illuminated tonight.
With no visual aids tonight, you’ll be able to see plenty on the moon’s surface, including: the Mare Crisium, Mare Tranquillitatis, and the Mare Vaporum. If you’ve got a pair of binoculars, you’ll get great views of some of the moon’s mountains, the Apennine and Alps mountain ranges. Finally, with a telescope, you’ll also be able to see the Apollo 17 and 16 landing spots and the Caucasus Mountains.
When is the next full moon?
The next full moon will be on Oct. 6. 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.
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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.
