Across
- 4. The study of the universe
- 9. A telescope that uses a lens to collect the light from an object
- 12. A collection of stars held together by gravity
- 17. A meteoroid that hits Earth’s atmosphere and burns up
- 19. The small group of galaxies that include our galaxy the Milky Way
- 20. A stream of fast moving charged particles produced by the sun
- 21. A graph that compares the properties of stars
- 28. The brightness of a star as seen from Earth
- 29. The phenomenon in which one celestial object moves directly in front of another celestial object
- 30. The average distance between Earth and the Sun
- 32. A meteoroid that is large enough to pass through Earth’s atmosphere and reach the ground without being burned up
- 33. An object composed of rocky material, ice, and gas
- 35. A telescope that uses a mirror to collect light from an object
- 37. A massive explosion in which the entire outer portion of a star is blown off
- 39. A group of planets that circle one or more stars
- 40. The change in frequency of a light or sound source due to its motion relative to an observer
- 42. The force of attraction between all masses in the universe
- 44. A scientist who studies astronomy
- 45. The event that may have triggered the expansion of the universe
- 46. The time it takes for an object to orbit another object
- 47. The theory that describes how stars and planets form
- 49. A star that is so dense that only neutrons can exist in its core
- 50. A huge collection of stars, planets, gas, and dust all held together by gravitational forces
- 51. A vast cloud of gas and dust
- 52. An optical instrument that produces a spectrum from a narrow beam of light
- 53. A piece of rock moving through space
Down
- 1. The most abundant invisible form of matter in the universe
- 2. A collection of up to 50 to 1000 stars
- 3. A hot, condensed object at the center of a nebula
- 5. A small, dim, hot star
- 6. The monthly progression of changes in the appearance of the moon
- 7. A celestial body made of hot gases
- 8. The radiation left over from the big bang
- 10. The rising and falling of ocean waters as a result of the moon and Earth’s gravity
- 11. A narrow band of stars on the H-R diagram
- 13. A star’s total energy output per second
- 14. An artificial object or vehicle that orbits the Earth
- 15. A large cluster of 4 to 25 clusters of galaxies
- 16. A group of stars that seem to form a distinctive pattern in the sky
- 18. An area of strong magnetic fields on the photosphere of the sun
- 22. The movement of an object in the sky from east to west
- 23. Certain specific wavelengths within a spectrum shown as lines
- 24. The turning of an object around an imaginary axis running through it
- 25. The phenomenon in which the full moon passes into Earth’s shadow
- 26. A form of energy that makes up almost three quarters of the universe that increases the expansion of the universe
- 27. A small object that ranges in size
- 31. The process of energy production in which hydrogen nuclei combine to form helium nuclei
- 34. An object that orbits one or more stars and doesn’t share its orbit with another object
- 36. The phenomenon in which the shadow of the moon falls on Earth’s surface
- 38. Any object that exists in space
- 41. The surface layer of the sun
- 43. A way of showing days that is organized into a table or chart
- 48. The distance that light travels in one year