Solar System Models
What model places the Sun at the centre?
Answer: Heliocentric.
What galaxy do we live in?
The Milky Way
What causes day and night?
Answer: Earth’s rotation.
What is orbit?
Answer: The path an object follows around another object.
What planet is known as the Red Planet?
Answer: Mars.
What model placed Earth at the centre?
Answer: Geocentric.
What is a light-year a measure of?
How long does one rotation take?
Answer: About 24 hours.
What is gravity?
Answer: A force that pulls objects toward each other.
What is the closest star to Earth?
The Sun
Why did scientists change from the geocentric model to the heliocentric model?
Answer: New observations and evidence supported the heliocentric model.
What is the observable universe?
Answer: The part of the universe we can see.
What causes a year?
Answer: Earth’s revolution around the Sun.
What is the Solar System?
Answer: The Sun and all objects that orbit it.
What planet do humans live on?
Answer: Earth.
Give one reason the heliocentric model was not accepted straight away.
Religious beliefs
Cultural traditions
Limited technology
People trusted old ideas
Approximately how many minutes does sunlight take to reach Earth?
Answer: About 8 minutes.
How long does one revolution take?
Answer: About 365 days.
What is a galaxy?
Answer: A large group of stars, gas and dust.
True or False: The Moon makes its own light.
Answer: False.
What force helps explain why planets orbit the Sun?
Gravity
How wide is the observable universe (approximately)?
Answer: About 93 billion light-years.
What is the difference between rotation and revolution?
Answer: Rotation is spinning on an axis. Revolution is moving around another object.
What is the Universe?
Answer: Everything that exists, including space, stars and galaxies.
What gas do humans need to breathe to survive?
Answer: Oxygen.