Where is the solar system in the universe?
What is the observable universe?
How far into the universe can we see without a telescope?
How does light travel through the universe?
What existed before the big bang?
What is the cosmic background radiation?
Is the universe expanding?
What is the universe expanding into?
What are high-energy cosmic rays?
Focus on: gamma-ray bursts: outshining the universe
Where did matter come from?
What do we know about black holes?
What are micro black holes?
Are there planets orbiting stars besides the sun?
Is there life in other parts of the universe?
Focus on: the universe's largest magnets
Could the universe be made of strings?
Could there be universes besides our own?
