Podcast
Play an AI-generated podcast conversation about this lesson
Questions and Answers
What is a galaxy?
What is a galaxy?
- A cluster of black holes and nebulae
- A collection of comets and asteroids
- A group of planets held together by gravity
- A large group of stars bound together by gravity (correct)
How many stars are estimated to be in our galaxy?
How many stars are estimated to be in our galaxy?
- 400 billion stars
- 200 billion stars (correct)
- 100 billion stars
- 300 billion stars
What is a protogalaxy?
What is a protogalaxy?
- A galaxy with an elliptical shape, almost void of dust
- A galaxy with a spiral shape and arms wrapped around a center
- A galaxy with no specific shape, mostly cloud-like
- A galaxy believed to have originated from collisions between older galaxies (correct)
Why can't the center of the Milky Way be seen clearly?
Why can't the center of the Milky Way be seen clearly?
Signup and view all the answers
How old is the Earth according to the passage?
How old is the Earth according to the passage?
Signup and view all the answers
What was the initial land that formed Earth made of?
What was the initial land that formed Earth made of?
Signup and view all the answers
What does the passage compare the expansion of the universe to?
What does the passage compare the expansion of the universe to?
Signup and view all the answers
When did the Big Bang occur, according to the passage?
When did the Big Bang occur, according to the passage?
Signup and view all the answers
What is believed to have caused the appearance of oxygen in the atmosphere?
What is believed to have caused the appearance of oxygen in the atmosphere?
Signup and view all the answers
What were the initial components of the primitive atmosphere on Earth?
What were the initial components of the primitive atmosphere on Earth?
Signup and view all the answers
