Across
- 2. The speed at which a galaxy moves away from an observer due to the expansion of the universe.
- 5. The pattern of colors or wavelengths produced when light is separated, used to study stars and galaxies.
- 7. The shortening of light wavelengths when an object moves toward the observer.
- 8. The astronomer who discovered that galaxies are moving away from us and that the universe is expanding.
- 10. A possible future of the universe where expansion stops and everything collapses back together.
- 12. A mysterious form of energy thought to be responsible for the accelerating expansion of the universe.
- 13. The stretching of light toward longer (red) wavelengths when an object in space is moving away from us.
- 14. Invisible matter that does not emit light but is detected through its gravitational effects on galaxies and cosmic structures.
- 15. The theory that the universe began from an extremely hot and dense state and has been expanding ever since.
Down
- 1. The change in the observed frequency or wavelength of a wave due to the motion of the source relative to the observer.
- 3. The exact density of the universe needed to make its expansion slow down and eventually stop (border between open and closed universe).
- 4. The scientist who used one of the first telescopes for astronomy about 300 years before modern cosmology.
- 6. The bending of light caused by massive objects like galaxies, acting like a cosmic magnifying glass.
- 9. The number that describes how fast the universe is expanding, relating galaxy distance to recession velocity.
- 11. The observation that galaxies move away faster as their distance from Earth increases.