Across
- 4. - an extremely luminous explosion of a star
- 5. unit - a standard unit of length used in astronomy to describe distances within our solar system
- 9. hole - a region in space where the gravitational field is so strong that nothing, not even light, can escape
- 10. - a large collection of stars, gas, dust, and dark matter held together by gravity
Down
- 1. system - a group of planets, dwarf planets, and other objects orbiting around a star
- 2. - the study of the universe and celestial objects
- 3. microwave background - the afterglow of the Big Bang, a pervasive glow of microwave radiation throughout the universe
- 6. - a luminous celestial object consisting of a mass of gas held together by gravity
- 7. - a cloud of gas and dust in space, often visible as a bright patch in the night sky
- 8. - a unit of astronomical distance equal to the distance light travels in one year