Across
- 3. the alternate rising and falling of the sea, usually twice in each lunar day at a particular place, due to the attraction of the moon and sun.
- 4. a celestial object consisting of a nucleus of ice and dust and, when near the sun, a “tail” of gas and dust particles pointing away from the sun
- 7. the action of rotating around an axis or center.
- 12. an eclipse in which the sun is obscured by the moon.
- 15. an eclipse in which the moon appears darkened as it passes into the earth's shadow.
- 17. either of the two times in the year, the summer solstice and the winter solstice, when the sun reaches its highest or lowest point in the sky at noon, marked by the longest and shortest days.
- 20. Newton's law of universal gravitation states that every particle attracts every other particle in the universe with a force which is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.
- 21. a tide just after a new or full moon, when there is the greatest difference between high and low water.
- 23. distinct period or stage in a series of events or a process of change or development.
- 24. a tide just after the first or third quarters of the moon when there is least difference between high and low water.
- 25. the curved path of a celestial object or spacecraft around a star, planet, or moon, especially a periodic elliptical revolution.
- 26. the fully shaded inner region of a shadow cast by an opaque object, especially the area on the earth or moon experiencing the total phase of an eclipse.
Down
- 1. the time or date (twice each year) at which the sun crosses the celestial equator, when day and night are of equal length
- 2. an artificial body placed in orbit around the earth or moon or another planet in order to collect information or for communication.
- 5. a fixed luminous point in the night sky which is a large, remote incandescent body like the sun.
- 6. a group of stars forming a recognizable pattern that is traditionally named after its apparent form or identified with a mythological figure
- 8. a celestial body moving in an elliptical orbit around a star.
- 9. a small body moving in the solar system that would become a meteor if it entered the earth's atmosphere.
- 10. a large, bowl-shaped cavity in the ground or on the surface of a planet or the moon, typically one caused by an explosion or the impact of a meteorite or other celestial body.
- 11. a forcible overthrow of a government or social order, in favor of a new system.
- 13. an imaginary line about which a body rotates.
- 14. a small body of matter from outer space that enters the earth's atmosphere, becoming incandescent as a result of friction and appearing as a streak of light.
- 16. an obscuring of the light from one celestial body by the passage of another between it and the observer or between it and its source of illumination.
- 18. a machine in which cloth or paper is pressed by rollers to glaze or smooth it.
- 19. a large, level basalt plain on the surface of the moon, appearing dark by contrast with highland areas.
- 22. the partially shaded outer region of the shadow cast by an opaque object.