WEBVTT

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Is the Earth getting
lighter or is it gaining weight?

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Our planet weighs
almost 6 septillion kilograms.

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This can be determined
fairly accurately with

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the help of satellites and
a mathematical formula.

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The Earth's weight
is constantly changing.

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It has enough gravity
to retain its atmosphere.

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But in the upper layers of gases,
gravity is no longer sufficient,

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and lighter elements,
such as hydrogen and helium,

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disappears into outer space.

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The Earth loses
around 96,000 tons

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of weight this way each year.

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Radioactive decay reduces
the weight of our planet, too.

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This converts matter into energy,
which then escapes

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into space as radiation.

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This happens mainly in
the Earth's interior and in rocks

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such as autunite
 near the surface.

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Radioactive decay accounts
for  around seven tons

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of weight loss every year.

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Space travel also lowers
the Earth's weight.

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When we send rockets into
space to transport satellites

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and exploration robots
to other celestial bodies,

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the building material that
these high-tech machines

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are made of
comes from Earth.

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Space exploration lightens the planet
by around 1,000 tons per year.

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But the Earth is not just losing
weight, it’s also gaining it!

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Partly thanks to a constant trickling
down of dust from outer space.

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This cosmic dust comes from
asteroids orbiting the Sun

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behind Mars, and above all,
from comets.

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Sometimes we can
even see these specks of dust

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as shooting stars.

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And every now and then, larger chunks
crash to the ground as meteorites.

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All of this adds an extra 16,000 tons
of weight to the Earth each year.

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So, doing the math, we end up

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with a weight loss
of 81,000 tons per year.

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Which means the Earth
is getting lighter.

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But only by
a tiny fraction of a percent.

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Almost nothing.