MCQ Detailed View

Answer: 10,000 km

The Earth’s atmosphere is made of several layers that together stretch up to about 10,000 kilometers above the Earth’s surface. Scientists divide it into five main layers: the troposphere, stratosphere, mesosphere, thermosphere, and exosphere. The lower layers hold most of the air we breathe and control weather and climate, while the upper layers gradually thin out into space.

The Kármán line, at around 100 km, is often used as the boundary between Earth and space for aviation and space law. However, the atmosphere does not suddenly stop there. Above it lies the thermosphere and the exosphere, which is the outermost region. The exosphere is extremely thin and extends thousands of kilometers. In fact, traces of atmospheric particles can be detected up to 10,000 km. Beyond this distance, scientists have observed a faint outer cloud called the geocorona, which can reach as far as 100,000 km, but it is so thin that it merges with space.

For exams like PPSC, FPSC, CSS, and UPSC, the generally accepted answer is that the Earth’s atmosphere extends to about 10,000 km. This value includes the exosphere, which fades gradually until it blends into outer space.