1The Moon's Invisible Magnet
Have you ever wondered why the ocean seems to have a mind of its own? Even though the Moon is about 238,000 miles away from Earth, it acts like a giant, invisible magnet. This celestial neighbor has a force called gravity that pulls on everything on our planet. While the ground is too solid to move much, the liquid water in our oceans is much easier to move! As the Moon orbits the Earth, its gravitational pull creates a "bulge" of water that follows it across the globe. This massive movement of water is what we see as high tide when we visit the beach.
2Two Bulges for a Spinning Planet
It might surprise you to learn that there isn't just one water bulge—there are actually two! While the Moon pulls the water on the side of the Earth closest to it, it also pulls the solid Earth itself. This leaves behind another bulge of water on the opposite side of the planet. Because the Earth is constantly spinning like a giant top, every coastal town usually passes through these two bulges once every 24 hours. This explains why most beaches experience two high tides and two low tides every single day, keeping the seashore in a constant state of motion.
3When the Sun Joins the Team
The Moon isn't the only star in the show! Our Sun is much, much larger than the Moon, but it is also much further away, so its pull on our oceans is a bit weaker. However, twice a month during the New Moon and the Full Moon, the Sun and the Moon line up perfectly. When they align, their gravitational forces combine into a "super-pull." This creates what scientists call Spring Tides. During a Spring Tide, high tides are much higher and low tides are much lower than usual. It is a powerful reminder of how objects in space work together to shape our world!
