To solve this problem, we use the formula:
 F = G m1 m2 / r^2
 where F is gravitational force, G is constant, m1 and m2 are masses while r is the distance between the two asteroids
 Since G m1 m2 is constant, therefore:
 F1 r1^2 = F2 r2^2
 So if r2 = 2 r1:
 (1,000,000 N) (r1^2) = F2 * (2 r1)^2
 F2 = 250,000 N
It was divided by 4