What would happen to an object orbiting in space if gravity were increased decreased or taken away?
Which gravity increased or decreased or taken away? In orbit around what? Your question is missing information – without knowing what gravity is being affected (the entire universe, just our galaxy, or just the object this thing is orbiting) there is no way to answer. If the object is orbiting the Earth, and the gravitational field of the Earth itself were to increase without an increase in the object’s orbital speed, the object would be pulled closer to the Earth so its orbit would be lower in altitude (and it could end up crashing to Earth). Similarly, if the Earth’s gravity were to decrease without a decrease in the orbital speed of the object, it would recede (its orbit would increase in altitude). If the gravity of the Earth were to vanish, the object would continue in a straight line tangent to its orbital path at the point where the gravity disappeared. You know, if you just think about things for a tiny bit its amazing how easily you can figure out questions like this.
