The movement of the earth around the sun is very Goldilocky. Did it happen over the years as the orbit of earth averaged out into how it is now? Is there any chance of it (orbit) changing by itself in the future without the interference of external factors?
Also how is it so stable? And what drives it? Is the sun pulling it once it is far away, gains speed, goes around the sun and as it goes away it again loses speed due to the sun's gravity and the whole cycle repeats?