| Answer | Crossword Clue |
|---|---|
| OORT | Dutch astronomer Jan |
| OORT | Comet astronomer, Jan Hendrik |
| OURS | Dutch astronomer |
| OORT | Dutch astronomer |
| BOK | Dutch-American astronomer. |
| OORT | Dutch astronomer for whom a cloud is named |
| OORT | Dutch astronomer who lent his name to a cloud |
| OORT | Dutch astronomer who found the first evidence of dark matter |
