The L1 point lies between the Earth and the Sun. For a small object at the L1 point, the gravitational forces from the Sun and the Earth, and the centrifugal force as it orbits the sun must balance. Consider the Earth and the Sun have masses $M_1=5.97\times10^{24}$kg and $M_2 = 2\times10^{30}$kg  respectively. The distance between them is $1$ AU. Find the distance to L1 from Earth in AU.