It is falling. It has to fall, that is the law of gravity. Otherwise, it would leave Earth in a straight line. But if it falls at exactly the rate it needs to fall to travel in an orbit, we call that "orbiting". If if falls faster than that, it crashes into Earth. If if falls less than that , it travels into space.

Question

It is falling. It has to fall, that is the law of gravity. Otherwise, it would leave Earth in a straight line. But if it falls at exactly the rate it needs to fall to travel in an orbit, we call that "orbiting". If if falls faster than that, it crashes into Earth. If if falls less than that , it travels into space.

Answer 1

You mentioned the law of gravity, which explains the force of attraction between two objects with mass. In the context of your question, let's consider a satellite in orbit around the Earth.

To understand why a satellite orbits the Earth instead of either crashing or flying off into space, we need to consider the balance between two factors: the satellite's speed and the shape of its orbit.

First, let's talk about speed. The satellite needs to move at a specific speed in order to maintain a stable orbit. This is called the orbital velocity. The orbital velocity depends on the mass of the Earth and the distance between the satellite and the center of the Earth. By calculating the orbital velocity using the specific formula, you can determine the minimum velocity required for a satellite to stay in orbit at a given altitude.

Now, let's consider the shape of the orbit. Most satellites travel in elliptical orbits around the Earth. An ellipse is an elongated circle with two foci. The Earth sits at one of these foci. When a satellite's speed matches the necessary orbital velocity, the resulting elliptical orbit allows the satellite to continuously fall towards the Earth while also moving forward. This creates a balance between the pull of gravity and the satellite's forward motion, allowing it to stay in orbit without crashing or drifting away into space.

If the satellite were to fall faster than the required orbital velocity, it would not be able to maintain a stable orbit. Instead, it would descend towards Earth, potentially resulting in a crash. On the other hand, if the satellite fell at a slower speed, it would gradually move away from Earth and venture into space.

In summary, the key factors in determining whether a satellite crashes, orbits, or travels into space are its speed (specifically, the required orbital velocity) and the shape of its orbit. By striking the right balance between gravity and forward motion, a satellite can stay in a stable orbit around the Earth.