| Answer | Crossword Clue |
|---|---|
| APOGEE | Top of the orbit |
| EAST | Direction of the moon's orbit |
| RETROGRADE | Like the orbit of Halley's Comet |
| APSIS | Point in orbit of the moon. |
| APOGEAL | Of a point in the moon's orbit. |
| ELLIPSE | Shape of the orbit of a planet. |
| APSIS | Point in the orbit of the moon. |
| ECLIPTIC | The plane of the earth's orbit around the sun |
| EIGHTYEIGHT | Number of days it takes Mercury to orbit the sun |
