Formation of Solar System

The moon probably formed when...

• A piece of the Earth broke off due to it's fast rotation
• A Mars-sized object rammed into the Earth
• Earth captured the moon gravitationally as it attempted to pass by.
• the molten bubble of the Earth budded.

Nebula's are mixtures of gases and what?

• clouds
• stars
• tiny particles
• dust

What do the outer planets have in common? 

• They are much larger than Earth and are made mainly of Hydrogen and Helium 
• The are about the same size as Earth and are mostly made of Hydrogen and Helium
• They are must larger than Earth and are mainly made of iron
• They are the same size as Earth and are mainly made of iron

Earth and the other planets closest to the Sun are made mostly of _______

• gas
• metal
• water
• rock

The planets of the solar system formed as 

• the center of the gas cloud cooled
• planetesimals flattened into a rotating disk
• planetesimals collided into one another
• the sun absorbed extra gas and dust from the solar system

What force acted on the massive nebula to collapse it and eventually form our sun?

• electrostatic force
• strong force
•  weak force
• gravity

What is the nebular hypothesis?

• Prediction about how the universe was formed
• Prediction of how the moon was formed
• Prediction of how comets were formed
• Prediction of how the Solar System was formed

A cloud of gas and dust from which bodies in space are formed

• photosphere
• nebula
• solar flare
• Sunspot

What is a small body from which a planet originated in the early stages of development of the solar system called?

• inertia
• planetesimal
• terrestrial planet
• gas giant

What is the term for Earth being in the center?

• geocentric
• heliocentric
• sun centered
• Galileo