Why doesn't the vacuum of space suck out our atmosphere?

Question

Why doesn't the vacuum of space suck out our atmosphere?

Answer 1

Our gravity holds our atmosphere to the Earth.  A much smaller body, like the mood or an asteroid, doesn't have sufficient gravity to hold an atmosphere.

Answer 2

our vacum of space sucks out our atmosphere because of the gravity forces in space.

Answer 3

All matter has gravity - and gravity sucks.

Answer 4

A vacuum is the absence of matter. It doesn't have a pull or push.

When we see a gas rush to fill a vacuum, the atoms move because they are pushed by their own pressure. They have an electric charge and they are also moving and bumping into each other (heat energy).

The gas remains under pressure here at ground level because gravity is pulling it towards the Earth's center.

If the Earth's gravity disappeared, the air would indeed quickly dissipate into space.

Answer 5

While some atmosphere is lost to space on a regular basis, most of the air is held in place quite well by the gravity of the earth.  If the Earth was smaller, like Mars, we would have a big problem.

Answer 6

Because Earth's gravity is strong enough to keep a hold of it. I believe the planet's magnetic field also plays a role.

Answer 7

Our planet's gravity holds our atmosphere from escaping into space. Our Moon has no atmosphere because the gravity on moon is not sufficient to hold its atmosphere.

The presence of atmosphere also depends on the presence or absence(also the strength) of magnetic field of a planet. Mars which had atmosphere once has no atmosphere now because Mars lost its magnetic field and the atmosphere vanished from mars.

When there is no magnetic field protecting a planet, the sun's electrically charged emissions hit the atmosphere and make the gases escape into space by heating them.

Even some amount of Earth's atmosphere is escaping into space continuosly from poles because the charged particles of the sun will be deflected to our poles by our planets magnetic field. But this is a negligible amount, it will take billions of years for the atmosphere to become considerably less.

Answer 8

Because the atmosphere has weight.

Earth's gravity hold it down.

Any bit of matter must reach escape speed (11 km/s) or, at least, orbital speed (7 km/s) to end up "in space".

This is true for atmospheric molecules.

Heat is "conserved" as movement by atoms and molecules.  Temperature is a measure of how fast the atoms move among themselves.

Some of the lighter atoms and molecules (e.g., hydrogen) do reach escape speed while in the upper atmosphere and some of our atmosphere does "leak" out.

But not much.

Answer 9

Because the earth has a gravitational field which is strong enough to hold it.