human
What are the most popular questions that people have about astrophysics?
assistant
1. Why is the sky blue?
2. How do stars form and evolve?
3. How did the universe begin?
4. What is dark matter?
5. Is there life beyond Earth?
6. How does gravity work?
7. What is the speed of light?
8. How many planets are there in our galaxy?
9. How did life begin on Earth?
10. What is a black hole?