Across
- 4. of energy through a substance
- 6. approximately 778million km from the Sun
- 8. number 17
- 9. force of gravity acting between Earth and Moon keeping moon on circular path
- 12. from one peak to another
- 17. stellar distances
- 18. the stars
- 19. released in sun's core makes its way to surface
Down
- 1. star
- 2. combining two stars
- 3. fragment of a molecular cloud forming a star
- 5. 13 cluster
- 7. atomic particle
- 10. 45
- 11. increase of wavelength of radiation
- 13. planet with an approximate diameter of 48000km
- 14. Russell diagram
- 15. body found between Mars and Jupiter
- 16. that emits beams of electromagnetic radiation