Across
- 3. a proton or neutron
- 5. 99.9% mass of the atom, a cluster of electrically positive protons and electrically neutral neutrons.
- 7. a natural satellite orbiting a planet or cosmic body.
- 10. a pure substance consisting of only atoms of the same number of protons in the nucleus.
- 12. late latin for star
- 14. a contracting mass of gas, stage of the birth of a star.
- 15. all existing matter and space as a whole
- 16. Bang the beginning of the universe through a rapid expansion of matter at extremely high densities and temperatures
Down
- 1. a celestial body moving in orbit around a star.
- 2. relating to the universe, outside of earth.
- 3. the process of creating new atomic nuclei from preexisting nucleons and nuclei
- 4. a system of stars, gas and dust held together by gravitational attraction
- 6. Horizon a boundary around a black hole not even light can escape from.
- 8. radiation a type of radiation ranging from visible light, radio waves, gamma wave and x rays.
- 9. a cluster of interstellar clouds visible from dark silhouettes against luminous matter.
- 11. a luminous spheroid held together by gravity.
- 13. a loop of a celestial object around a planet or star taking a certain amount of time