12 reasons not to get a PhD. (CBS Moneywatch) COMMENTARY Earning a doctorate is widely considered to be an excellent way to boost a person's lifetime earnings potential. 1. A PhD takes twice as long as a bachelor's degree to complete.
The International Space Station orbits Earth in this layer. mesopauseâthe boundary between the mesosphere and the thermosphere; the coldest place on Earth. mesosphereâthe layer in which most meteors burn up after entering Earthâs atmosphere and before reaching Earthâs surface. stratopauseâthe boundary between the mesophere and the stratosphere. stratosphereâcontains the ozone layer; the layer where volcanic gases can affect the climate. tropopauseâthe boundary between the stratosphere and troposphere. troposphereâthe layer closest to Earthâs surface in which all weather occurs.
The thermosphere is the layer of Earth's atmosphere that still contains substantial molecules of heavier gases. It occurs below the outermost layer, the exosphere, which consists mainly of a near-vacuum of hydrogen and helium.