- What is a universe?
- What is a solar system?
- What is a galaxy?
- What is a galactic cluster?
- What is a planet? Give an example.
- What is a moon? Give an example.
- What is a sun?
- What is a dwarf planet? Give an example.
- How old is the universe?
- How old is the solar system?
- How old is earth?
- What are the planets in our solar system?
- What is a white dwarf?
- What is a red giant?
- What is a supernova?
- What is a pulsar?
- What is a quasar?
- What is a blazar?
- What is a magnetar?
- What is a black hole?
- Is the universe expanding, contracting or staying stable in size? How do we know?
- What is the composition of the universe (what is it made of)? How do we know?