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A layer of double-deckers covering the Earth

No one can hear you scream, throw up or hear your brains exploding out of your ears in space. All of these are very real possibilities. Space is a very difficult place to live. Even the most challenging places on Earth like Antarctica or Death Valley are like a day trip to Porthcawl compared with space.

So, why aren't we throwing up and why aren't our brains coming out of our ears on Earth?

Imagine a double-decker bus; now imagine a layer of concrete as tall as a double-decker bus covering the Earth. That’s the same as a bomb shelter with walls five metres thick. So, we're not all throwing up because the atmosphere presses down with a force of about 10.3 tonnes on every square metre of the Earth’s surface. That’s quite a lot of protection!

Death Valley


How does the atmosphere protect the Earth?

Fifty-thousand tonnes of charged particles, radiation from the sun, cosmic rays from exploding stars and micrometeorites hit the Earth everyday. All of this material is very hazardous to life.

So how come we're not all looking like fried eggs?

Well, the Earth has a fantastic dense protective atmosphere about 100km thick. Luckily, this is like a cosmic armour plating that shields the Earth from constant bombardment from space.

What would happen to the seas if the atmosphere disappeared?

With no atmospheric pressure liquid water would boil, and it wouldn't matter what temperature it is. So, without atmospheric pressure the Earth’s oceans would boil away into space.

Graphical representation of the Earth's oceans boi


What would happen to the Earth’s temperature?

The average temperature on the Earth is about 15C (59F). With no atmosphere, the temperature would swing between a blistering 101C (213.8F) in the sunlight to a very chilly -184C (-299.2F) in the shade. The highest temperature ever recorded on Earth was a staggering 70.7C (159.26 F) in the Iranian desert in 2005. The lowest temperature ever recorded was -71.2C (-96.16F) in Siberia in 1926.

What would happen to you?

You would suffocate!

The effects of no atmosphere

If the atmosphere did vanish you would suffocate. Without oxygen a human being can only survive for about five minutes. You probably wouldn't live that long though.

Your blood would either boil or freeze!

Remember, most body organs are made up of about 70 per cent water. Blood is made up of 83 per cent water so your blood would boil before you suffocated. If you were in the shade, it would freeze solid.

Is there any way you could survive?

Well, you could try running very quickly between the sun and the shade to even the temperature out. If you did manage to get these little problems cracked, the radiation would get you anyway. So, the atmosphere is really very useful!

How can humans survive in space?

There’s no atmosphere to protect you in space so the only way you could survive there is to carry your own atmosphere around with you. This is not an easy task. This images below show what a portable atmosphere looks like.

A portable atmosphere : modern day space suits
Buzz Aldrin walking on the moon.  Neil Armstrong i


Could you be a human satellite?

Airlock and Spacesuit like those used for Alexi Le

The first person to ‘walk’ in space was a cosmonaut called Alexei Leonov in 1965. He was the first person to know what it is like to float freely above the Earth like a human satellite. He was very lucky to survive. When he left his spacecraft he discovered that without any air pressure to balance the air pressure inside the suit, it blew up and became as stiff as a rugby ball.

Alexei found that he could barely even bend his arms. He found it impossible to pull himself back into his spacecraft. He was forced to make a decision: the only way he would be able to get back into his spacecraft was to reduce the pressure inside the space suit so that he could bend his arms.

He didn't know if reducing the pressure would cause him to suffocate and black out. In the end, he opened the valve little by little and with an incredible effort of will managed to pull himself back inside the spacecraft just before losing consciousness.

Early space suit design

The early space suit design had many problems. Perhaps the biggest one of all was that it had no cooling system so astronauts tended to overheat. Gene Cernan (American astronaut and last man on the moon) got so hot he had to abandon the walk. He lost over a litre of water as sweat. Some of the sweat steamed up his helmet so he couldn’t see what he was doing.

Space suits were soon fitted with a cooling system and a dehumidifier. They also work at a much lower pressure, about 0.26 of atmosphere. This is high enough to have a sensible boiling point for body fluids but low enough so that the astronauts can move their arms and legs! The newer suits have more oxygen so that the astronauts can breath easily.

Imagine being hit by a high velocity bullet!

Yr Orsaf Ofod Ryngwladol

The shuttle and the International Space Station orbit the Earth at 28163.52km per hour (17,500 miles per hour). That's 20 times the speed of sound. At this speed you could go from New York to Paris in 11 minutes and London to Cardiff in 27 seconds.

When an astronaut is in orbit, he or she is moving very, very fast. At this speed if you run into a piece of space debris it’s going to hurt! Space suits are made to absorb tiny micrometeorites without puncture but they can’t stop anything bigger than a grain of sand. It would be like being hit by a high velocity rifle bullet. All spacesuits are reinforced with Kevlar armoured layers. In the end though, it’s down to luck!

So, fancy becoming an astronaut?

If this article hasn't put you off, select the link below to apply to become an astronaut:

European Space Agency

European Space Agency

Good luck!

The big questions:

The Apollo space suit weighs about 13 stone on Earth. How could the astronauts walk around so easily carrying so much stuff?

Why has the Earth got an atmosphere while the moon has none?

Why do the pilots of the ‘Black Bird’ spy plane wear space suits?

Why could using high oxygen content atmospheres be very dangerous?