Gravity-Powered Asteroid Tractor Proposed to Thwart Impact

After reading the article "Gravity-Powered Asteroid Tractor Proposed to Thwart Impact", answer these questions in complete sentences.

1. In meters, what is the size of the asteroid mentioned in the first paragraph ?
2. What is the mass of the proposed spacecraft ?
3. Describe the interaction between the "asteroid tractor" and the asteroid.
4. What analogy is used to describe the gravity attraction that pulls the asteroid and spacecraft together ?
5. Why is a gentle thruster tug important ?
6. Why are the spacecraft thrusters angled ?
7. How much force do the thrusters produce ?