Words in this exercise:
| Word | Meaning |
| Aperture | a small opening in something |
| Asterism | a prominent pattern or group of stars |
| Blue Moon | a second full moon in a calendar month |
| Declination | the angular distance from the celestial equator |
| Epoch |
a period of time in history
|
| Equinox | day and night of the same length |
| Free fall | move under the force of gravity only |
| Heliocentric | considered in relation to the centre of the sun |
| Lunar | connected with the moon |
|
Meridian
|
an imaginary line between the two poles |
| Synodic | of or relating to stars and planets |
| Zodiac | diagram showing the position of planets |
