| Halley, e.g. |
| Hubble, for one |
| Galileo was one |
| Cosmos scientist |
| Galileo, for one |
| Satellite tracker |
| Copernicus, notably |
| Tycho Brahe, for one |
| Sky-at-night observer |
| One who knows what's up? |
| Apt anagram of MOON STARER |
| His business is looking up |
| One who is always looking up |
| What a mixed-up "moon-starer" really is |