Space Words

2. a model in which the Sun is at the center and the planets orbit around it.
3. motion, The apparent backward movement of a planet across the sky as seen from Earth, caused by the relative motions of Earth and the planet.
5. A large celestial body that orbits a star and does not produce its own light.
7. One of the two days each year when the Sun reaches its highest or lowest point in the sky at noon, resulting in the longest day (summer solstice) or shortest day (winter solstice).
11. Unit (AU),A unit of distance equal to the average distance between Earth and the Sun, about 149.6 million kilometers (93 million miles).
15. unit of distance, not time. It is the distance that light travels in one year through space, which is about 9.46 trillion kilometers (5.88 trillion miles).
17. extremely bright and distant object powered by a supermassive black hole at the center of a galaxy, emitting enormous amounts of energy.

1. A massive, glowing ball of hot gas that produces energy through nuclear fusion. The Sun is a star.
4. A vast collection of stars, gas, dust, and dark matter held together by gravity. Earth is in the Milky Way.
6. ancient astronomical instrument used to measure the positions of stars and planets and to help with navigation and timekeeping.
8. precision instrument used for measuring horizontal and vertical angles, commonly used in surveying and astronomy.
9. North Star
10. A small rocky object that orbits the Sun, most of which are found in the asteroid belt between Mars and Jupiter.
12. A small icy object that orbits the Sun and develops a glowing coma and tail when it gets close to the Sun.
13. One of the two days each year when day and night are approximately equal in length because the Sun is directly above Earth's equator.
14. A large cloud of gas and dust in space where stars can form or where remnants of dead stars can be found.
16. hole, A region of space where gravity is so strong that nothing, not even light, can escape from it.