(d) The troposphere starts at the Earth’s surface and extends 8 to 14.5 kilometres high (5 to 9 miles).This part of the atmosphere is the most dense. Almost all types of weather are there in this region.The stratosphere starts just above the troposphere and extends 50 kilometres (31 miles) high. The mesosphere starts just above the stratosphere and extends to 85 kilometres (53 miles) high. Meteors burn up in this layer. The thermosphere starts just above the mesosphere and extends to 600 kilometres (372 miles) high. Aurora and satellites occur in this layer.