Across
- 5. a circumstellar disc in the outer Solar System, extending from the orbit of Neptune
- 6. The planets Mercury, Venus, Earth, and Mars are
- 8. is a celestial event in which a number of meteors are observed
- 11. When a planet does not meet the three rquirments
- 12. the apparent motion of a planet in a direction opposite to that of other bodies within its system
- 13. a measure of how circular an orbit is
- 14. are long, curvilinear structures found on some planetary bodies
- 16. Planets in our solar system travel on this
- 17. is a large planet mostly composed of helium and/or hydrogen
Down
- 1. is a fundamental system in condensed matter sciences and the main constituent of gas giant planets
- 2. is an icy, small Solar System body that warms and begins to release gases when passing close to the Sun
- 3. a body that could or did come together with many others under gravitation to form a planet
- 4. a region of space between the orbits of Mars and Jupiter
- 7. When the meteoroid hits Earth's surface it turn into
- 8. A small body moving in the solar system that can turn into a meteor
- 9. This is when a meteoroid enters Earth's atmosphere it turns into a
- 10. Cloud activity on planets such as jupiter
- 15. How we measure distance in space