Changes

The '''atmosphere''' is the mass of air surrounding a [[planet]].<ref>Wile, Dr. Jay L. ''Exploring Creation With Physical Science''. Apologia Educational Ministries, Inc. 1999, 2000</ref>

The '''atmosphere''' is the mass of air surrounding a [[planet]].<ref>Wile, Dr. Jay L. ''Exploring Creation With Physical Science''. Apologia Educational Ministries, Inc. 1999, 2000</ref>

The term atmosphere is also a unit of [[pressure]]. An atmosphere is defined as the amount of pressure exerted by a column of [[air]] at [[sea level]]. This is equal to approximately 14.7 [[pound]]s per square [[inch]] on the earth.

The term atmosphere is also a unit of [[pressure]]. An atmosphere is defined as the amount of pressure exerted by a column of [[air]] at [[sea level]] in standard conditions. One atmosphere (atm) is defined as 101325 Pa. This is equal to approximately 14.7 [[pound]]s per square [[inch]] on the earth.

The earth's atmosphere insulates the earth's surface, making it around 15 degrees [[Celsius]] (27 degrees [[Fahrenheit]]) warmer than it would be without any air. This occurs through absorption of outgoing [[infrared rays]] by gas molecules like [[carbon dioxide]] and [[methane]]. This warming is known as the ''[[greenhouse effect]]''.  

The earth's atmosphere insulates the earth's surface, making it around 15 degrees [[Celsius]] (27 degrees [[Fahrenheit]]) warmer than it would be without any air. This occurs through absorption of outgoing [[infrared rays]] by gas molecules like [[carbon dioxide]] and [[methane]]. This warming is known as the ''[[greenhouse effect]]''.