Solar eclipses are among the most breathtaking events in nature. The idea of the moon blocking out the sun, even for just a few minutes, has fascinated humans for thousands of years. But one question always comes up: what phase is the moon during a solar eclipse?
The answer is simple but important—a solar eclipse always occurs during the new moon phase. Let’s dive deeper into why this happens, what makes eclipses so rare, and why this cosmic event is such a big deal.
What phase of the moon is the solar eclipse?
If you’re wondering what phase the moon is in during a solar eclipse, the answer will always be the same: the new moon phase.
Here’s why. The moon travels around Earth about once every 29.5 days, creating the familiar cycle of phases—new moon, crescent, quarter, gibbous, and full moon. A solar eclipse happens when the moon passes directly between Earth and the sun. This can only happen during the new moon phase, when the side of the moon facing Earth is in shadow.
So next time someone asks you, “What phase of the moon is the solar eclipse?” You’ll know the answer: new moon, every time.
What time is the partial solar eclipse on September 21, 2025?
Now that you know what phase the moon is in during a solar eclipse, let’s talk about the next one. On September 21, 2025, a partial solar eclipse will take place.
- Start time: 1:29 p.m. ET
- Peak eclipse: 3:41 p.m. ET
- End time: 5:53 p.m. ET
During this partial eclipse, the moon will only cover part of the sun. It will look like someone has taken a “bite” out of the sun’s glowing disc.
Sadly, this eclipse won’t be visible across the U.S. Instead, the best views will be from the South Pacific, New Zealand, Antarctica, and parts of Australia.
Even though it won’t be visible everywhere, it’s still a great reminder of what phase the moon is in during a solar eclipse—always the new moon.
What moon phase do eclipses occur in?
- People often confuse solar eclipses with lunar eclipses. Let’s clear that up:
- Solar eclipses: Only during the new moon phase.
- Lunar eclipses: Only during the full moon phase.
So, what phase is the moon during a solar eclipse? Always a new moon. What phase is the moon during a lunar eclipse? Full moon.
That distinction is key to understanding how these events work.
Is the Sun 400 times the Moon?
You might have heard this fascinating fact: the sun is about 400 times larger than the moon—but it’s also about 400 times farther away from Earth.
Because of this perfect size-and-distance ratio, the moon and sun appear nearly the same size in our sky. That’s the only reason solar eclipses are possible. Without it, we wouldn’t even be asking what phase the moon is during a solar eclipse, because eclipses as we know them wouldn’t exist.
This cosmic coincidence is one of the most incredible things about our solar system.
Why don’t we see a solar eclipse every new moon?
Now, if the phase of the moon during a solar eclipse is always a new moon, why don’t we see one every month?
The answer lies in the moon’s orbit. The moon’s path around Earth is tilted about 5 degrees compared to Earth’s orbit around the sun. That means most of the time, the moon passes slightly above or below the sun during the new moon.
Only when the new moon happens near the points where the moon’s orbit crosses Earth’s orbit (called nodes) do we get a solar eclipse. That’s why eclipses are special—they don’t happen every month.
How often do solar eclipses happen?
Solar eclipses occur two to five times a year, but they’re not always visible everywhere. Many happen over oceans or remote areas.
For example, the partial eclipse on September 21, 2025, is only visible in the Southern Hemisphere. People in the U.S. will miss out, but the event is still a global reminder of what phase the moon is in during a solar eclipse—always the new moon.
How to watch a solar eclipse safely
Knowing what phase the moon is in during a solar eclipse is one thing, but actually viewing an eclipse is another. Safety is critical. Looking at the sun directly can cause permanent eye damage.
- Here’s how to watch safely:
- Wear certified eclipse glasses (ISO 12312-2).
- Do not use regular sunglasses.
- Use telescopes, binoculars, or cameras only with proper solar filters.
- Never look through an unfiltered optical device while wearing eclipse glasses—it can burn through and damage your eyes.
- If you don’t have glasses, you can use a simple pinhole projector to see the eclipse indirectly.
- Solar eclipses vs. lunar eclipses
- Let’s quickly compare the two:
- Solar Eclipse: Happens during the new moon. The moon moves between Earth and the sun, blocking sunlight.
- Lunar Eclipse: Happens during the full moon. Earth blocks sunlight from reaching the moon.
So if you’re wondering again what phase the moon is in during a solar eclipse, the answer is always new moon, while lunar eclipses belong to the full moon.
Why solar eclipses feel magical
Solar eclipses have inspired myths, legends, and celebrations for centuries. Ancient cultures often saw them as omens, while today we understand the science behind them.
Yet even with all our knowledge, standing under the shadow of the moon as it crosses the sun is still a moving experience. It connects us to the larger universe and reminds us of the delicate balance in our solar system.
Final Thoughts
So, what phase is the moon during a solar eclipse? The answer is clear: only the new moon phase.
Whether it’s a total, partial, or annular eclipse, the moon must be new and perfectly aligned with Earth and the sun. Without that alignment, no solar eclipse can happen.
The next time you hear about an eclipse on the news—or see one for yourself—you’ll know the science behind it. And you’ll also remember why this question matters: what phase is the moon during a solar eclipse? It’s always the new moon.
What Phase Is the Moon During a Solar Eclipse?
Solar eclipses are one of the most awe-inspiring events in the sky. The idea of the moon partially or completely covering the sun has fascinated humans for thousands of years. But many people still ask: what phase is the moon during a solar eclipse?
The answer is simple—a solar eclipse only happens during the new moon phase. Let’s explore why that is, how solar eclipses work, and how you can safely enjoy this celestial show.
What phase of the moon is the solar eclipse?
If you’re curious about what phase the moon is during a solar eclipse, here’s the key fact: it’s always a new moon. During this phase, the moon sits directly between Earth and the sun, which allows its shadow to fall on parts of the Earth’s surface.
This alignment is what makes a solar eclipse possible. Without the moon being in the new moon phase, no part of the sun could be blocked.
Even partial eclipses, where the moon only covers a portion of the sun, require this exact moon phase. So, remembering what phase the moon is during a solar eclipse is essential for understanding how eclipses work.
What time is the partial solar eclipse on September 21, 2025?
The next solar eclipse is set for September 21, 2025, and it will be a partial solar eclipse. According to EarthSky, the timeline is:
- Start: 1:29 p.m. ET
- Peak: 3:41 p.m. ET
- End: 5:53 p.m. ET
During this eclipse, the moon will cover part of the sun, giving it the appearance of a “bite” taken out of its disc.
Unfortunately, this event won’t be visible from most of the U.S. The best viewing areas include New Zealand, parts of Australia, Antarctica, and the South Pacific. Even so, knowing what phase the moon is in during a solar eclipse helps astronomers and enthusiasts predict eclipses and plan observations.
What moon phase do eclipses occur?
- Solar eclipses and lunar eclipses are often confused. Here’s the difference:
- Solar eclipses: Only happen during the new moon phase.
- Lunar eclipses: Only occur during the full moon phase.
So whenever someone asks, ‘What phase is the moon during a solar eclipse?’ you can confidently say, ‘New moon.’ This is different from a lunar eclipse, where Earth blocks sunlight from reaching the full moon.
Is the Sun 400 times the Moon?
Here’s a fascinating fact about eclipses: the sun is roughly 400 times larger than the moon, but it is also about 400 times farther away from Earth.