There is no air in space because there is no gravity to condense the molecules of gases found there into air. On Earth, gravity holds nitrogen, oxygen and the other gases that compose the atmosphere together, but only to about 60 miles above the surface.Continue Reading
A few particles of dust and molecules of gases float in space. Scientists call this mixture interstellar medium. The particles and molecules in interstellar medium are so rare that many people think of space as a perfect vacuum. While it is closer to a perfect vacuum than anything man is able to create on Earth, it is not perfect. Interstellar medium is 99 percent gas, but the gas molecules are very far apart, and hydrogen is the most common gas in the mix. Interstellar dust particles are too small to see with the naked eye and are composed of silicates, iron, ice crystals and carbon.
The air at the surface of Earth has many molecules of gases in a small space. As the distance from the surface increases, the relative concentration of the gases decreases, meaning the air becomes thinner. At the 60-mile level, the concentration begins to change and the atmosphere is primarily lighter gases, such as hydrogen or helium, and closer to the composition of interstellar medium.Learn more about Astronomy
Humans cannot hear sounds in outer space, because in order for the human ear to detect sound, a sound wave must have a medium, like air or liquid, to push and travel through, eventually exerting that pressure on the eardrum and allowing the ear to hear the sound. There is not enough of a medium of molecules in space through which sound can properly travel, which is why the human ear cannot detect sound in outer space.Full Answer >
Saturn has no surface and is a giant ball of gas that is mainly made up of helium and hydrogen, while the atmosphere of the planet also consists of the same gases. A handful of unmanned missions that have visited Saturn throughout history show that the planet has no surface to land on and is not capable of supporting living things.Full Answer >
Four layers of the earth's atmosphere containing various gases make up the composition of the sky. The layers of the atmosphere are divided into the troposphere, the stratosphere, the mesosphere and the thermosphere. The atmosphere's divisions occur according to temperature fluctuations.Full Answer >
A star undergoes nuclear reactions that burn hydrogen and it forms when a cloud of gas collapses under gravity. Planets do not experience nuclear reactions, nor do they form from a cloud of gas.Full Answer >