Earth's atmosphere, which is around 300 miles thick, is mainly made of nitrogen and oxygen, although there are many other trace substances in its composition. Trace substances make up only 1 percent of the bulk of the atmosphere while nitrogen (78 percent), oxygen (21 percent) and argon (1 percent) make up the rest.Know More
The minority 1 percent contains a variety of things, including minute amounts of neon, carbon dioxide, helium, krypton, methane, nitrous oxide, hydrogen, iodine, ozone, xenon, ammonia and carbon monoxide. At lower altitudes, water vapor may also be present.
The early atmosphere of the Earth was not as hospitable as the current atmosphere. In fact, it was about 100 times more dense around 4.4 billion years ago when the earthy first cooled and was much more abundant in ammonia and carbon dioxide than it is today. Earth is the only planet known to sustain life since the atmosphere protects the planet from radiation and heat from the sun.
The atmosphere is divided into five layers, including the troposphere, stratosphere, mesosphere, thermosphere and exosphere. The layer closest to Earth is the troposphere. It's around four to 12 miles thick. Scientists know the least about the mesosphere since weather balloons and jets can't reach its height (31 to 53 miles above the Earth) and satellites orbit too high above it.Learn more about Earth Science
Nitrogen is important because it sees a significant amount of use in the agricultural sector: it is an additive in many commercial fertilizers and is sprayed on crop fields to reduce the risk of insect infestation and crop failure. Nitrogen is produced using natural gas and air, which are readily available in the environment. The availability of its raw materials makes nitrogen fertilizers and pesticides relatively easy to produce.Full Answer >
According to scientists, the earth is about 4.5 billion years old. However, because of the constant upheavals in climate, plate tectonics, asteroid strikes and other events, most of the evidence of the earth's beginnings are lost.Full Answer >
Astronomers theorize that over 4.5 billion years ago, Theia, an object about the size of Mars, collided with Earth to create a tilted axis. This is called "the giant impact theory." Prior to this event, the axis was straight at 180 degrees.Full Answer >
Air is a gaseous substance that is composed primarily of nitrogen, oxygen and argon. The air in the atmosphere that surrounds the Earth is approximately 78 percent nitrogen, 21 percent oxygen and 1 percent argon, with the remainder made up of various other gases including neon, helium and hydrogen.Full Answer >