Astronomy questions

Question:
1. Why is it hot at the equator and cold at the poles? Angle of the sunlight.
2. What causes the seasons? Tilt of the Earth's axis relative to the plane of the orbit.
3. What causes the tides? Gravitational pull of the Moon (and Sun slightly).
4. Describe the Solar System. Collection of planets etc.
5. What is a comet? Describe a typical comet's orbit. Ice and rock. Highly elliptical.
6. What are the asteroids and where are they? Large lumps of rock. Micro planets.
7. What holds the Solar System together? Gravitational attraction of the Sun.
8. What is a nebula? Gaseous – large clouds of (usually) hydrogen.
9. What is a galaxy? Huge collection (100 000 million) of stars.
10. What holds everything together in a galaxy? Gravitational attraction.
11. What is the Milky Way? The edge of our own galaxy.
12. Describe the Universe Difficult! Everything!