Space Crossword

1. the measure of how much an orbit deviates from being circular
3. the celestial equivalent of latitude, denoting how far (in degrees) an object in the sky lies north or south of the celestial equator
7. a telescope's main light-gathering lens or mirror
8. any prominent star pattern that isn’t a whole constellation, such as the Northern Cross or the Big Dipper
10. the edge of a celestial object's visable disk
11. a temporary dark blemish on the surface of the Sun that is a planet-size region of gas cooler than its surroundings
12. traditionally, something that happens rarely or never. more recently, this has come to mean the second full Moon in a single calendar month

2. when the Moon or a planet appears especially close either to another planet or to a bright star
4. the fraction of the moon or other body that we see illuminated by sunlight
5. a lens or mirror’s focal length divided by its aperture
6. the point in the sky that is directly overhead
9. an increase in meteor activity at certain times of the year due to Earth passing through a stream of particles along a comet’s orbit around the sun