Question

is the gravitational potential energy of two point masses infinitely away is taken to be zero then gravitational potential energy of a galaxy is​

Answer 1

If the gravitational potential energy of two point masses away infinitely is  zero then gravitational potential energy of a galaxy is​ negative.

• The potential energy of gravity is the potential energy that an object has because it is within a gravitational field.
• There is always a gravitational potential of two or more masses. Energy conservation allows this energy from the gravitational field to always be negative.
• The gravity wants to pull the test mass closer and closer at a separation of the Earth's surface. So the gravity-based work is negative. The gravitational energy potential is negative because we want to do the opposite of what gravity requires positive energy.