Final answer:
The worlds in our solar system have common characteristics that suggest they formed from the same 'mother cloud' or solar nebula. These include planetary motion, composition, and the formation process.
Step-by-step explanation:
The characteristics that the worlds in our solar system have in common, which lead astronomers to believe that they all formed from the same 'mother cloud' or solar nebula, include:
- Planetary Motion: All planets revolve around the Sun in the same direction and lie in nearly the same plane, indicating a common origin.
- Composition: The planets in our solar system are made of similar materials, such as rock and metal in the terrestrial (inner) planets and hydrogen and helium in the giant (outer) planets.
- Formation Process: The planets and other celestial bodies in our solar system formed from the solar nebula, a rotating cloud of gas and dust. The presence of planetesimals, comets, and asteroids further supports this idea.