Larger galaxies form from the merging of small protogalaxies. This process is similar to the formation of a. stars. b. planets. c. molecular clouds. d. asteroids.

Before we delve into galaxy formation, we need to understand what protogalaxies are.
A protogalaxy is a large cloud of gas and dust, which eventually collapses under its own gravity to form a galaxy.
They are the building blocks of galaxies, containing the raw materials for star formation.
At the beginning of the universe, these protogalactic clouds were composed mostly of hydrogen and helium.
Over time, these clouds underwent fragmentation and cooling processes.
This facilitated the formation of stars and other celestial objects.
The initial conditions in these protogalaxies, such as their mass and density, determined their pathways to becoming galaxies.
Some grew to become large spiral or elliptical galaxies, while others remained as dwarf galaxies. Understanding protogalaxies helps us comprehend the origins of our universe's vast and diverse galactic structures.

The merging process is pivotal in the formation of larger galaxies.
Small protogalaxies collide and combine to form more massive galaxies.
This process is driven by gravitational interactions.
When two protogalaxies come close enough, their mutual gravitational attraction pulls them towards each other.
This usually results in a chaotic collision, although it happens over incredibly long timescales.
Over millions of years, these collisions lead to the merging of these protogalaxies.
This merging doesn't just lump the protogalaxies together; it also triggers intense star formation known as starbursts.
The overall structure and energy dynamics of the resulting galaxy depend on factors like the sizes, masses, and relative velocities of the merging protogalaxies.
This process of galactic mergers continues to shape the universe even today.

Asteroids, much like galaxies, also go through a formation process that involves merging.
Unlike galaxies, though, asteroids form on a much smaller scale.
Asteroids are formed from the accretion of dust, rock, and metal.
In the early solar system, particles in the protoplanetary disk collided and stuck together, gradually forming larger and larger bodies.
These smaller bodies eventually combined to form asteroids.
This accretion process is very similar to how protogalaxies merge to form larger galaxies.
Both processes involve the gravitational attraction and collision of smaller entities to form something larger and more complex.
Understanding asteroid formation can thus provide insights into the larger scale process of galaxy formation and evolution.