What is a huge cloud of dust and gas in space called?
Nebula
What force pulls dust and gas together?
Gravity
What happens when mass increases?
Gravity becomes stronger
What does it mean when planets orbit in the same plane?
They move on the same flat surface
Which planet spins the opposite way and contradicts the theory?
Venus
Why can’t we observe a Solar System forming?
It takes millions of years
What tool do scientists use to test how Solar Systems form?
Computer models
What kind of facts or data do scientists use to support their ideas?
Evidence
What does the word “support” mean in science?
It agrees with or helps explain an idea
