Across
- 2. line A bright line of a spectrum, indicating the wavelength of emitted light.
- 5. The path one object takes to travel around another object.
- 10. Each different shape of the Moon.
- 12. A streak of light in the sky from gravel- and pebble-sized meteoroids; also known as a shooting star.
- 13. An imaginary axle that a planet spins on.
- 15. moon The phase of the Moon that occurs when the Moon is opposite the Sun as seen from Earth.
- 16. A cloud of gas and dust in space between stars.
- 17. A day of the year when the Sun's rays shine straight down on the equator.
- 21. A change in land created by an impact.
- 23. Belt The region of the solar system beyond the orbit of Neptune; plutoids are located here.
- 24. A layer of gases that surround an object, held in place by
- 28. A planet orbiting a star other than the Sun.
- 29. A small- or medium-sized piece of rock or metal from space.
- 30. fuel The remains of organisms that lived long ago preserved as oil, coal, or natural gas.
- 31. planet An object that orbits the Sun and is big enough to be round but doesn't clear away all objects near its orbit
- 33. An object that orbits a star and is massive enough for its own gravity to force it into a spherical shape.
- 36. Light-colored areas of the Moon with lost of rough mountains and craters.
- 40. The sum total of all things that can be observed or detected.
- 41. Earth's natural satellite.
Down
- 1. light Wavelengths of electromagnetic radiation that can be seen by the human eye.
- 3. The dark surface of cooled magma in a flooded crater.
- 4. Crater A crater that has central peaks and ejecta thrown out in long rays.
- 6. A force of attraction between masses.
- 7. giant The stage of a star when it becomes very large and has a relatively cool surface.
- 8. A chunk of ice, dust, and rock, material a few kilometers in size.
- 9. eclipse When Earth is exactly between the Moon and the Sun, and the Moon passes through the Earth's shadow.
- 11. A small, rocky object that orbits the Sun.
- 14. Pertaining to the Moon.
- 18. Period How long it takes an object to orbit another object.
- 19. Star The reference star pointed to by Earth's North pole.
- 20. of reference The assemblage of objects, distances, and directions that you use to establish the location of something.
- 22. spectrum The range of electromagnetic radiation arranged in order of energy level.
- 25. A representation of thinking to help others understand your thinking.
- 26. system A region of space occupied by a system of objects orbiting a star, such as the Sun and all things orbiting it.
- 27. The path one object takes to travel around another object.
- 32. Way The name of the galaxy that our solar system is a part of.
- 34. dwarf The stage of a star when it has no more fuel for nuclear reactions.
- 35. An enormous collection of tens of millions to hundreds of billions of stars, interstellar gas, and dust.
- 37. A collection of interacting parts.
- 38. A Moon shape that is larger than a first or third quarter Moon, but smaller than a full Moon.
- 39. Bang Theory A theory that one explosion created the universe,