approximately how many kilometers (miles) above earth's surface does the atmosphere end and outer space begin?
Best Answer: the earth has five atmospheres: troposphere, stratosphere, mesospere, thermosphere, and exosphere. the top of the exosphere is about 360 miles above the earth, once your out of this you are in outerspace, most people would consider 55000 feet (9 miles) to be space because you can see the curve of the earth and the sky is darker. By the same token, space is often defined as beginning at the lowest altitude at which satellites can maintain orbits for a reasonable time – which is approximately 160 kilometers (100 miles) above the surface. These varying definitions are complicated when one takes the definition of the word “atmosphere” into account. The stratosphere extends between 11 and 31 miles (17 to 50 kilometers) above the earth's surface. The earth's ozone layer is located in the stratosphere. Ozone, a form of oxygen, is crucial to our survival; this layer absorbs a lot of ultraviolet solar energy. At a height of 128,000 feet (39 km), the force of gravity is only 1% less than at the surface of the Earth. Before the jump, he was held up by the helium balloon and capsule, unlike the free-fall orbit of the International Space Station. From Wikipedia: Three quarters of the atmosphere's mass is within 11 km of the planetary surface. In the United States, persons who travel above an altitude of 80.5 km (50.0 miles)are designated as astronauts. The International Space Station also orbits in this layer, between 320 and 380 km (200 and 240 mi), and needs to be constantly boosted because friction with the atmosphere still occurs. The outermost layer, known as the exosphere, extends out to an altitude of 10,000 km (6214 mi) above the planet. The space station orbits the Earth at height of about 200 miles (350 km) at a speed of about 17,000 MPH (28,000 km/hr), taking about one and a half hours per orbit around Earth. Astronauts aboard are weightless because their space ship is falling freely. Its rocket engines are turned off and nothing is holding it up. The Karman line, at 100 km (62 miles), is also frequently used as the boundary between atmosphere and outer space. For all intents and purposes, space starts at about 62 miles. And no, it has absolutely zero to due with the Earth's gravity. Meteors flare about 12 kilometers up. If you've ever seen the northern or southern lights (auroral displays), those are about 90 kilometers (~55 miles) high. The International Space Station orbits between 330 and 410 kilometers (205-255 miles) above Earth's surface and well above the atmosphere. Space begins about 100 km (62 miles) above Earth's surface. Astronauts routinely live and work in space, but must live in special environments and wear space suits to work where there's no air to breathe and temperatures are extreme. NASA.
100 km.