Across
- 1. Explosive death of a massive star.
- 3. Unseen matter accounting for gravitational effects.
- 7. Subatomic particle with almost no mass.
- 8. Extremely bright and distant celestial object.
- 9. High-energy radiation from outer space.
- 12. Process of combining atomic nuclei.
- 13. Increase in wavelength of light due to motion.
- 14. Region of spacetime with strong gravitational pull.
- 15. High-energy electromagnetic radiation.
Down
- 2. Boundary beyond which nothing can escape.
- 4. Early stage of a star's formation.
- 5. Atoms with same element but different neutrons.
- 6. left over from the Big Bang.
- 10. Point of infinite density in a black hole.
- 11. Interstellar cloud of gas and dust.