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What Would Happen If The Moon Disappeared

(dramatic instrumental music) (clicking)

- [Announcer] Our moon is on the move.

Each year it drifts an estimated 1.5 inches

further away from Earth and in the process,

Earth's rotation is actually slowing down.

What if one night the moon simply disappeared?

Would we miss it?

(dramatic instrumental music)

A full moon is on average 14,000 times brighter

than the next brightest night sky object, Venus.

Without it, every night would be as dark as a new moon

and stargazing would be spectacular,

but by the next morning,

you'd begin to realize just how important the moon is

for life on Earth.

To start, between the sun, Earth's rotation, and the moon,

the moon has the largest influence on Earth's tides.

Without it, high and low tides would shrink

by an estimated 75%.

This would jeopardize the lives of many types of crabs,

muscles, and sea snails that live in tidal zones

and disrupt the diets of larger animals who rely on them

for food, threatening entire coastal ecosystems

in the process.

Within a few decades,

we would start to see mass population declines

in the sea and on land.

One of the largest spawning events in the world occurs

in the Great Barrier Reef.

Each November in the days following the light

of a full moon, corral colonies across the Reef,

spanning an area larger than the state of New Mexico,

release millions of egg and sperm sacks

within nearly minutes of one another.

Scientists are certain that the full moon plays a role

in the timing, but exactly how remains a mystery.

On land, animals like these red crabs also use lunar cues

to reproduce.

After living most of their lives on the mountains,

millions of adult crabs migrate down to shore

and then only during the last quarter of the moon,

females release their eggs into the sea.

Now, the moon may not hold as much sway

over human reproduction, but without it,

something we care equally about would change, the weather.

(thunder rolling)

Tides and tidal currents help mix cold, Arctic waters

with warmer waters in the tropics.

This balances temperatures

and stabilizes the climate worldwide.

Without the moon,

weather forecasts would be practically impossible.

The average difference between the hottest

and coldest places on Earth could grow

to life-threatening extremes,

but none of this compares to the biggest change

that we would have coming over the next millennium.

Right now, Earth tilts on an axis at 23.5 degrees,

mostly due to moon's gravity.

If the moon disappeared, Earth's axis would wobble

between anywhere from 10 to 45 degrees.

Some experts estimate

that Jupiter could help keep Earth's tilt

from reeling completely out of control,

but even just an extra 10-degree tilt could wreak havoc

on the climate and seasons.

In the past, Earth's tilt has changed

by about one to two degrees,

which scientists think could have caused Ice Ages

in the past.

It's hard to know what a 10 degree

or 45 degree tilt would do,

but probably nothing good for most life on Earth.

The moon isn't just imperative for life on Earth today,

experts believe that it might have also played a key role

in the formation of life more than 3.5 billion years ago.

Turns out, the moon isn't just a beacon of light

in the night sky.

Its existence is crucial to the delicate balancing act

that makes life here possible.

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