Across
- 6. conducted spectogrpahic studies in the 1920s
- 7. depends on on the observation of the proper notion and doppler shift
- 8. is an event when a planet crosses in front of a star as viewed by an obsever
- 11. helps in the understanding of the size of the universe
- 12. parallax defined as the angle subtended at the object by the semi-major axis of earths orbit
- 13. this theory perfectly explains the abundance of helium and hydrogen in the universe
- 14. can be determined by the time elapsed since its brith
Down
- 1. it makes use of the fact that as a planet moves towads or away from us
- 2. the process of determining the distance to star cluster
- 3. this theory proposed that there was no beginning to the universe nor there be an end
- 4. the age of the universe
- 5. it only orbits around the sun and has enough gravity pull itself into spherical shape
- 9. is a planet that does not orbit the sun
- 10. cmoes from the greek word wanderer