Across
- 2. Leftover heat signal from the early universe, abbrev. (3)
- 4. Proposed the heliocentric model in 1543 (10)
- 6. Most abundant material in the universe
- 7. Invisible medium scientists once thought light travelled through (5)
- 8. Cause of galaxies moving apart (9)
Down
- 1. Calculated initial space temperature in Kelvin (4 digits)
- 2. Einstein added this "constant" to keep the universe still (13)
- 3. Came up with the primeveal atom model (8)
- 5. Galaxies shift toward this colour as they move away (3)