Outer space is a void that lies beyond the uppermost ranges of the atmosphere of Earth and between all other objects in the universe. Although it is considered to be a void, outer space can be thought of as an environment in itself. Radiation and objects pass freely through it. A human or another living being in the outer space environment without any protection would not survive even for a few moments.
Total vacuum
The basic environmental characteristic of outer space is the vacuum for the nearly total absence of gas molecules. The gravitational attraction of large bodies, such as planets and stars, pulls the gas molecules close to their surfaces, which leaves the space between them practically empty. Stray gas molecules are usually found between these bodies. Their density is so low that they can be thought of as being unreal.
Effect of pressure in outer space
On Earth, the atmosphere applies pressure in all directions. At sea level, it is 101 kilopascals but in space, it is almost zero. With no external pressure, the air within a human’s lungs, without any kind of protective shield, would immediately rush out into the vacuum.
Effect of pressure in space on humans
The sudden absence of external pressure that balances the internal pressure of the body would damage delicate tissues such as the eardrums and the capillaries. The body would swell, causing tissue damage and a lack of oxygen supply to the brain. This would result in unconsciousness in under 10 seconds. Dissolved gases in the body fluids would expand, causing the skin to stretch much like a pumped balloon. Bubbles would form in the bloodstream making it ineffective as transport of oxygen and nutrients to the body’s cells.
Temperature in space
The temperature in outer space is hazardous. The objects that receive sunlight in space and are at Earth’s distance from the Sun, can scale to over 120 °C while those on the shaded side can be as low as – 100 °C. Because of the space environment, a comfortable temperature range cannot be sustained, posing grave problems.
Other environmental factors
There are other environmental factors in space such as microgravity, radiation of the electrically charged particles from the Sun, ultraviolet radiation and meteoroids. Meteoroids are small bits of rock and metal leftover from the formation of the solar system about trillions of years ago and from comets and asteroids collisions. They are small but travel at very high velocities and can easily seep into the human skin. Debris from previous space missions is also very dangerous. A tiny paint chip traveling at thousands of kilometers per hour can do significant damage.
Compiled by Madhurani Chavan