Hi guys, I'm confused when my textbook (or actually most other explanations) says that when an object is launched at a speed high enough, it orbits the earth circularly because the earth beneath CURVES away from it. First thing first, I'll start by visualizing the earth is stationary and don't rotate. This is for the sake of making things simpler first. If I throw a ball at a high speed, it will eventually reach the ground. If the speed is very high, the ball will "escape" from Earth. Right? To complicate things further, when the earth rotates, it will orbit. One thing is, does the earth rotate faster than the ball's orbiting speed? The text does not mention it :( . If it does, how does it go into orbit? Even if the earth curves away, wouldn't it still fall down? I'm thinking that if the speed is high enough, the ball can reach up quite high till there is sufficient space for it to orbit. Because at lower heights, it will eventually collide onto the ground although it wants to orbit circularly. At higher heights, this is then possible. What has it got to do with curving anyway? And I find the diagrams given by textbooks are peculiar. For instance, the Earth rotates sideways but object is launched from places like North Pole to South Pole, vertical orbit when the rotation is horizontal. What difference would it even make then? By the way, is the orientation for launching an object to escape earth and launching an object to orbit the same? Is it upwards and tangentially respectively?