| Abbreviation | Definition |
|---|---|
| PACS | Photoconductor Array Camera and Spectrometer |
| PAGASA | Philippine Atmospheric Geophysical and Astronomical Service Administration |
| PAGASA | Philippine Atmospheric Geophysical and Astronomical Services Administration |
| PAGASA | Philippine Atmospheric Geophysical and Astronomical System Associationb |
| PAGASA | Philippine Atmospheric Geophysical Astronomical Services Administration |
| PAGASA | Philippine Atmospherics Geophysical and Astronomical Services Administration |
| PAGASA | Philippines Atmospheric Geophysical and Astronomical Services Administration |
| PAO | Portable Astronomical Observatory |
| PAR | Photon Activity Rate |
| PASA | Pan-Arab Space Agency |
| PASJ | Publications of the Astronomical Society of Japan |
| PBO | Pine Bluff Observatory |
| PC | Planetary Contrast |
| PCS | Pointing Control System |
| PDS | Planetary Data System |
| PEC | Periodic Error Correction |
| PEGA | Programs in Extra Galactic Astronomy |
| PET | Peak Ejection Time |
| PGC | Principal Galaxy Catalog |
| PHA | Potentially Hazardous Asteroid |