In space no one can hear you scream. This is because there is no air in the space – it is a vacuum. Sound waves can not travel through a vacuum.
“Cosmos” begins about 100 km above the Earth, where the shell of air surrounding our planet disappears. In the absence of air in order to disperse the sunlight and produce blue sky, space appears as a black blanket dotted with stars.
The space is generally considered that it is completely empty. But this is not the case. The gaps between the stars and planets are filled with huge amount of spray of gas and dust. Even empty space part comprising at least a few atoms or molecules per cubic meter.
The space is also filled with many forms of radiation that are dangerous for astronauts. Much of this infrared and ultraviolet radiation comes from the sun’s high-energy X-rays, gamma rays and cosmic rays – particles travelling at nearly the speed of light – arrive from distant star systems.
Space images gallery