Gravity is the mother of all forces. It is an inter-body force. Think of rain water flowing all around. It pours uniformly over an area. But some of it goes underground. Some flow to the river and then to the sea. Others to fields. Some form a lake or fill a pond. Everywhere, the confinement encountered changes the nature of the same water. In the same way, gravity resolves into different forces. An interaction involves two bodies. Depending upon the nature of confinement, the same thing can exhibit different characteristics. Think of quarks, mesons and proton/neutrons. They are constituted of the same stuff, but exhibit different characteristics only because of their nature of confinement. There is no bare mass or bare charge. Energy confined is matter and matter released is energy. They are not convertible, but their proportions can vary. When energy dominates, we call the packet charge. When matter (confinement) dominates, we call it mass. Depending upon the nature of confinement, magnitude of charge (move out) and mass (close in) exhibit characteristics of proximity or distance variables. Proximity-Proximity variable is strong interaction. Proximity-Distance variable is beta decay of weak interaction. Distance-Proximity variable is electromagnetic interaction. Distance-Distance variable is alpha decay. These interactions, when further combined linearly or non-linearly, generate all forces of nature. Theoretically, there are 122 different functions done by the same energy.
In the solar system, as well as everywhere else, the two bodies revolve around a common barycenter. For example, the Sun and Earth revolve around a point within the Sun (just over 30,000 km from the center). In the Earth–Moon system, where the barycenter is located on average 4,671 km from the Earth's center, well within the planet's radius of 6,378 km. The Sun–Jupiter barycenter would be approximately 55,000 km from the center of the Sun. Gravity keeps the bodies stable in their respective orbits. However, the different systems interact with each other as a single point source. This makes them wobble in their orbits. Why is it so?
The answer to atomic, planetary, star and galactic orbits, is symmetry. There are four types of interactions depicting four types of motion (कर्म). Strong interaction (अन्तर्याम) in macro world is compression (आकुञ्चन), which, in the micro world leads to creation of new particles. This is perpetual motion (नित्यगति). Beta decay (वहिर्याम) leads to dispersing (प्रसारण), which retains the particles within a fixed boundary (सम्प्रसाद गति). In the macro world, this provides friction. Electromagnetic radiation (उपयाम) leads to moving away from higher concentration to lower concentration (अवक्षेपण), which leads to interaction with others (यज्ञगति). Alpha decay (यातयाम) is radioactive decay (साम्परायगति), which leads to separation of a part of the atom (उत्क्षेपण) that is reduced to another atom. Thus, these four constitute two pairs of oppositely symmetrical interactions that are present in every particle – whether explicitly as charge or implicitly as stable (opposite charges balancing each other). Without this balance, no particle can be stable. These are the 4 primordial element (भूत) known as पृथ्वी, अप्, अग्नि, वायु, respectively. The particles are retained in their places (उद्याम) in stable orbits at maximum distance (उरुगाय प्रतिष्ठा) by gravity through spinning motion (गमन) against a common center.