Across
- 3. the simplest and lightest chemical element
- 6. second lightest element in periodic table that is a colourless, odourless, and tasteless gas
- 7. when light from a distant galaxy appears to shift colours when it is moving toward us
- 8. famous scientist that is responsible for the theory of relativity
Down
- 1. a massive system of stars , stellar remnants, interstellar gas, dust, dark matter, planets bound together by gravity
- 2. space, time, matter, galaxies, stars, planets and cosmic structures
- 3. influential scientist that discovered that galaxies are moving away from each other
- 4. when light from a distant galaxy appears to shift colours when it is moving away from us
- 5. acronym for a faint radiation left everywhere in the visible universe from the Big Bang
- 9. a celestial object composed mostly of hydrogen and helium that emits heat and light