Are tides higher at full moon or new moon?

Full Moon vs. New Moon: Which One Really Pulls the Tides Higher?

Ever stood on a beach, mesmerized by the ocean’s ebb and flow? Tides are one of nature’s most reliable shows, and you’ve probably wondered if they’re bigger during a full moon or a new moon. Here’s the scoop: actually, you get the highest tides around both full and new moons. Sounds a bit weird, right? Let’s break down why.

Gravity’s Dance: The Moon’s Not Alone

Tides are basically huge, slow-motion waves caused mainly by the moon’s gravity tugging on our oceans. Think of it like this: the moon’s got a grip on Earth, and it’s pulling the water towards it. Now, Sir Isaac Newton figured this out way back in 1687. He explained how the moon’s “tidal force” makes the Earth—especially the water—bulge out. And get this, it bulges on both sides: the side facing the moon and the side opposite it! These bulges? That’s what we experience as high tide. The areas in between are where you find low tide.

Now, I know what you might be thinking: why a bulge on the far side of the Earth? It’s because the moon’s gravity is affecting the whole Earth, pulling at every point. The pull is strongest on the side closest to the moon, sure, but weakest on the opposite side. Plus, there’s inertia at play on the far side, kind of like the water’s trying to keep doing its own thing.

But wait, there’s more! The sun also gets in on the act, adding its own gravitational oomph to the tides, though it’s only about half as strong as the moon’s. Even though the sun’s way bigger, it’s also way farther away. And when it comes to tides, distance matters: tidal forces change a lot depending on how far away something is.

Spring Tides: When Everything Lines Up Just Right

Okay, so here’s where it gets interesting. The biggest, baddest tides happen during what we call “spring tides”. These happen roughly twice a month, during the new and full moon phases. That’s when the sun, Earth, and moon are all lined up, more or less, in a straight line. Think of it like a cosmic tug-of-war where everyone’s pulling in the same direction. During a spring tide, the combined gravity of the sun and moon creates super-high high tides and extra-low low tides. And just so you know, “spring tide” has nothing to do with springtime; it just means the tide is “springing forth.”

During a new moon, the moon’s hanging out between the Earth and the sun. During a full moon, we’re in the middle, with the Earth between the sun and the moon. Either way, the sun’s gravity is backing up the moon’s gravity, and the result is more extreme tides.

Neap Tides: When the Sun and Moon Argue

On the flip side, we have “neap tides.” These happen when the sun and moon are at right angles to each other, relative to Earth. This occurs during the first and third quarter moons. During neap tides, the sun and moon are kind of working against each other, so the tidal changes aren’t as dramatic. High tides are lower than usual, and low tides are higher than usual.

But Wait, There’s More! Other Things That Mess with Tides

The sun and moon’s alignment is the main act, but other things can change how high the tides get.

• The Moon’s Wobbly Orbit: The moon’s path around the Earth isn’t a perfect circle; it’s more of an oval. That means the distance between us and the moon changes throughout the month. When the moon’s closest (at perigee), its gravity is stronger, and we get higher tides. When it’s farthest away (at apogee), the tides are weaker. Sometimes, you get a “perigean spring tide,” which is when a new or full moon lines up with the moon being at perigee. Those tides can be seriously huge!
• Earth’s Own Wobble: Just like the moon, Earth’s orbit around the sun is also an oval. When Earth’s closest to the sun (at perihelion), the tides get a little boost.
• Local Quirks: The shape of the coastline, how deep the water is, and other local features can all change the timing and height of tides in different spots. I remember one time visiting the Bay of Fundy in Canada – the tides there are absolutely insane because of the bay’s shape!

The Takeaway

So, to sum it all up: you generally get higher tides during both full and new moons because of how the sun, Earth, and moon line up. But the actual height of the tide can depend on a bunch of other stuff, like how close the moon is and where you’re standing on the planet. It’s a complicated dance of gravity and geography, and it’s pretty amazing when you think about it.