What happens if the moon comes closer

The Moon is kept in orbit by the gravitational force that the Earth exerts on it, but the Moon also exerts a gravitational force on our planet and this causes the movement of the Earth's oceans to form a tidal bulge. Due to the rotation of the Earth, this tidal bulge actually sits slightly ahead of the Moon.

Some of the energy of the spinning Earth gets transferred to the tidal bulge via friction. This drives the bulge forward, keeping it ahead of the Moon. The tidal bulge feeds a small amount of energy into the Moon, pushing it into a higher orbit like the faster, outside lanes of a test track. This phenomenon is similar to the experience one feels on a children's roundabout. The faster the roundabout spins the stronger the feeling of being slung outwards.

But the energy gained as the Moon is pushed higher is balanced by a reduction in the energy of its motion - so an acceleration provided by the Earth's tides is actually slowing the Moon down. While 3. On early Earth, when the Moon was newly formed, days were five hours long, but with the Moon's braking effect operating on the Earth for the last 4.

We can see some evidence of the slowdown in the fossil records of some creatures. By looking at the daily growth bands of corals we can calculate the numbers of days that occurred per year in past periods, and from this we can see that days are getting longer, at a rate of 19 hours every 4. The length of a day, or in other words the rotation speed of the planet, plays a big part in its stability. Just like keeping a plate spinning on a stick, the key is to have the plate spinning fast, as if it slows down it crashes to the floor.

In a similar way, as the Earth's rotation slows down, our whole planet may start to slowly wobble and this will have a devastating effect on our seasons. The chunks of our former satellite would rain down on Earth and would look like as if hundreds and thousands of asteroids were falling down on us and wiping out entire cities in the process.

Once the moon began its trajectory towards our planet, it would increase the tidal impact it has on us. By the time it hit the Roche limit, it would be causing tides as high as 30, feet. Our world would be devastated by a horde of Tsunamis. However, for a short time, the hardcore surfers would enjoy riding some tasty waves.

On the other hand, it might become a solution to global warming. Take, for example, Jupiter's moon Io , the most volcanically active world in the solar system, Scarlett said. Io's volcanism results from the push and pull from the gravity of Jupiter and two of its other moons. Earth might see a similar fate if the moon were suddenly half as close.

Along with all the sudden buckling of the planet's crust, Earth's spin would slow over time. This is because, as the moon's gravity pulls the oceans, the resulting friction between the ocean floor and water slows Earth's spin. Today, Earth's rotation is slowing by about one-thousandth of a second per century, Comins said.

If the moon were half the distance away, Earth's rotation would slow even more, dragging out our days and nights. If we were to survive the sudden earthquakes, volcanic eruptions, lengthening of days and nights, and higher tides, at least we'd get to see more frequent solar eclipses. Because the moon would cover a larger area of the sky, it would be more likely to pass in front of the sun from our perspective, Comins said.

We'd even still be able to see the sun's corona outer atmosphere shining around the dark silhouette of the moon, but not as clearly, he added. Otherwise, the moon and its phases would look about the same, only bigger in the sky. And what if the moon were to slowly spiral toward Earth, rather than just moving suddenly?