An orbit is the curved path that an object takes around a larger object due to the force of gravity. In space, this can refer to the path of a planet around a star, or a moon around a planet.
Gravity is what keeps an object in orbit around another object. The larger object's gravity pulls the smaller object towards it, but the smaller object's velocity keeps it moving in a circular or elliptical path around the larger object.
The factors that can affect an orbit include the mass of the objects involved, their distance from each other, and their velocity. Other factors such as atmospheric drag and other external forces can also have an impact.
If the velocity of an object in orbit is increased, it will move into a higher orbit. If the velocity is decreased, it will move into a lower orbit. This is because the speed and direction of an object's orbit are directly related to its velocity.
Yes, an orbit can change over time due to various factors such as the gravitational pull of other objects, atmospheric drag, and external forces. This is why spacecraft and satellites often need to make adjustments to their orbits to maintain their desired path.