This is one of the questions on a small exercise but I don't understand it. I thought that the Earth is in orbit because the mass of the Earth and the Sun combine perfectly such that the orbital velocity is exactly the same as the pull of the sun so the Earth is forever falling towards it. If this is the case, then any significant change to the mass would (I'm actually not sure) alter the magnitude of the pull, causing the Earth to either slowly spiral into the Sun or away from it, kind of like a satellite orbiting the Earth. So wouldn't any change to the Sun's mass kill us? That was my first thought, then it occurred to me that the Sun has solar flares which expel tons and tons of mass. So technically the Sun should be getting less massive and it's been doing this for at least 4.5 billion years cause that's how old the Earth is. So with this is mind, I have no idea how the Earth isn't spiralling away from the Sun as we speak. These are the 2 thoughts I had on this question and I really don't know how to answer it.