Universe

3. a tide just after the quarter moons when there's the least difference between high and low water
5. a galaxy shaped like a pinwheel, with a central nucleus and spiral arms extending outward
6. a large cloud of dust and gas where stars where gigantic explosion throws matter out into space
9. the spiral-shaped galaxy in which the Sun and earth's solar system are located on a spiral arm about 3/4th away from the center
10. chemical reaction where the nucleus of two atoms combine to form a new element
12. longest or shortest day of the year where the sun is shining more on one of Earth's hemisphere
13. a tide just after a new or full moon when there is the greatest difference between high and low water
15. how dense, dim core of natter left after a star dies

1. as earth rotates, water is pulled up onto the shore, bulging at parts of earth that force directly toward or way from the moon
2. the motion of an object that orbits or travels around another object
4. the rise and fall of sea levels that usually occur twice daily changing every 6 hours, caused by the moon's gravity
7. The brightness of a star determined by the amount of EM energy a star emits
8. systems of dust,gas, stars and interstellar matter
11. end stage of supermassive stars where gigantic explosion throws matter out into space
14. force that pulls matter together forming stars or holding moons and planets in orbit around stars