Which layer of the atmosphere is known as the farthest from the Earth?

The exosphere is regarded as the outermost layer of the Earth's atmosphere, positioned farthest from the Earth's surface. It begins at an altitude of about 600 kilometers (approximately 375 miles) and extends outward, gradually fading into outer space. Within the exosphere, atmospheric particles are extremely sparse, and they can travel hundreds of kilometers without colliding with one another. This layer serves as a transition between Earth's atmosphere and outer space, where the influence of gravity is weak, allowing particles to escape into space.

In contrast, the other layers—troposphere, stratosphere, and mesosphere—exist much closer to the Earth's surface. The troposphere is the lowest layer where weather occurs, the stratosphere contains the ozone layer, and the mesosphere is located above the stratosphere. Thus, the exosphere stands apart from these layers due to its vast altitude and unique characteristics, making it the correct answer to the question.