Answer:
F' = 2F
Step-by-step explanation:
The gravitational force of attraction between asteroids is given by Newton's Law of Gravitation:
where,
F = Force
G = Universal Gravitational Constant
m₁ = m₂ = m = mass of each asteroid
r = distance between asteroids
Therefore,
--------------------- eq(1)
Now, if we double the mass of one asteroid:

using equation (1):
F' = 2F