Across
- 4. The point nearest Earth's center in the orbit of the Moon or an artificial satellite
- 6. Earth period of time extending from about 4.6 billion years ago
- 8. a regular oval shape
- 9. a huge collection of gas, dust, and billions of stars and their solar systems
- 10. the slow change in the direction of Earth's rotational axis.
- 14. Eclipse happens when the Moon passes between the Sun and Earth, casting a shadow on Earth that either fully or partially blocks the Sun's light in some areas
- 16. The motion of an object around a point, especially around another object or a center of mass
- 19. having or representing the earth as the center, as in former astronomical systems.
Down
- 1. The point farthest from Earth's center in the orbit of the Moon or an artificial satellite.
- 2. that the universe began as just a single point, then expanded and stretched to grow as large as it is right now—and it is still stretching!
- 3. having or representing the sun as the center, as in the accepted astronomical model of the solar system.
- 5. the branch of science that deals with celestial objects, space, and the physical universe as a whole
- 6. of the Moon
- 7. Hypothesis idea that a spinning cloud of dust made of mostly light elements, called a nebula, flattened into a protoplanetary disk, and became a solar system consisting of a star with orbiting planets
- 11. the action of rotating around an axis or center.
- 12. rocky, airless remnants left over from the early formation of our solar system about 4.6 billion years ago
- 13. frozen leftovers from the formation of the solar system composed of dust, rock, and ices
- 15. Eclipse occurs when the Sun, Earth, and Moon align so that the Moon passes into Earth's shadow
- 17. Waves a mechanical wave of acoustic energy that travels through the Earth or another planetary body
- 18. he curved path of a celestial object or spacecraft around a star, planet, or moon,