| Answer | Crossword Clue |
|---|---|
| HALLEY | Famous English comet discoverer. |
| HALE | Comet discoverer Alan |
| ALAN | Comet co-discoverer Hale |
| HALLEY | Comet discoverer (1656-1742). |
| DONATI | Italian astronomer, comet-discoverer |
| ALANHALE | Comet co-discoverer who shares his name with a father-and-son acting pair |
