The exosphere is the outermost layer of Earth's atmosphere, extending from about 600 kilometers (373 miles) above the surface to around 10,000 kilometers (6,200 miles). In this region, the atmosphere is extremely thin, and particles are so sparse that they can travel hundreds of kilometers without colliding with one another. The exosphere primarily consists of hydrogen and helium, along with trace amounts of other gases. This layer gradually transitions into outer space, where the effects of gravity are minimal. Satellites, such as those used for communication and weather monitoring, often orbit within the exosphere. Understanding the exosphere is essential for studying space exploration and the behavior of satellites.