| Answer | Crossword Clue |
|---|---|
| PTOLEMY | Second-century astronomer |
| PTOLEMY | Influential second-century astronomer |
| PTOLEMY | Second-century astronomer and mathematician |
| PTOLEMY | Influential second-century Greek astronomer and geographer |
| OMAR | 11th century astronomer-poet. |
| HALLEY | British astronomer of 18th century. |
| METON | Athenian astronomer of Fifth Century B. C. |
| GAUSS | Renowned 19th-century German mathematician and astronomer |
