Earth and Space Sciences

3. the reaction inside stars that create heat and light
6. the acronym for the type of electromagnetic waves left over from the creation of the universe
8. the hottest and brightest colour of star
9. a collection of stars based in a confined area of space
10. the distance between the Sun and the Earth (about 150 million km)
12. the category of star larger than main sequence stars
14. the category of star larger than giants, and which produce supernovae and black holes after they have used up their fuel
16. the distance light travels in one Earth year (about 9.5 trillion km)
19. the current era of the universe (based on the formation of stars)
21. the distance between angles of stars based on trigonometry (about 31 trillion km)
23. the current age of the Sun is ____ billion years

1. the category of star smaller than the Sun
2. the current age of the universe is roughly ___ billion years
4. a collection of star-forming gas in space
5. the name of the system of planets, dwarf planets and other objects that orbit the Sun
7. the theory that explain the beginning of the universe
11. the group of stars with predictable changes in their size and brightness during their lifecycle
13. the name of the closest galaxy to the Milky Way
15. the main fuel for stars
17. way the name of the galaxy the Solar System belongs to
18. the science of analysing and categorising stars
20. the early age of the universe before stars formed
22. the official name of the Sun