astronomy
Across
- 2. It must orbit a star. It must be big enough to have enough gravity to force it into a spherical shape. It must be big enough that its gravity cleared away any other objects of similar size near its orbit around the Sun.
- 3. to get less and less, or to decline.
- 7. moving around itself
- 9. longest and shortest day of the year
- 10. spring summer winter and fall
- 13. lean
- 14. a curved path
- 15. mix of gasses that surround a planet
Down
- 1. a force that attracts things
- 3. a moon that gets more sunlight on it as the days go by
- 4. is any moon that appears more than half-lighted but less than full
- 5. the shape of a moon that is less than half-illuminated
- 6. day night equal length
- 8. very long-period waves that move through the ocean in response to the forces created by the moon
- 11. an oval
- 12. any massive self-luminous celestial body of gas that shines by radiation derived from its internal energy sources.