Many meteorites appear to have formed very early in the solar system's history. how do these meteorites support our theory about how the terrestrial planets formed

The appearance and composition of meteorites is what we would expect if metal and rock condensed and increased as our theory suggests.

Explanation:

The planets and most of their satellites were formed by accretion of matter that accumulated around the largest pieces of the proto-nebula. After a chaotic succession of collisions, mergers and reconstruction processes, they acquired a size similar to the current one and moved until they were in the positions we know.

The area closest to the Sun was too warm to retain light materials. That is why the inner planets are small and rocky, while the outer ones are large and gaseous. The evolution of the Solar System has not stopped, but, after the initial chaos, most of the materials are now part of bodies located in more or less stable orbits.

Any theory that attempts to explain the formation of the Solar System should take into account that the Sun rotates slowly and only has 1 percent of the angular momentum, but it has 99.9% of its mass, while the planets have 99% of the angular momentum and only 0.1% of the mass. One of the explanations argues that, at first, the Sun was much colder; The density of its materials was slowing its rotation, while warming, until a certain balance was achieved.

it is given that trillions of microbes make up to 1% to 3% of the body mass.

let's take average of this percentage: 2%

consider the average mass of the human body as 70 kg.

then, trillions of microbes would have mass  

therefore, 100 trillion micro-organisms would weigh:

this is an approximate value and could change depending on the mass of the human body and percentage of the microbes present in it.

average mass per microorganism =