- Physikalisches Institut [Gießen]
- Physique des plasmas
- Planetary and Space Sciences Research Institute [Milton Keynes]
- Polar Research Institute of China
- Politecnico di Milano [Milan]
- Polska Akademia Nauk = Polish Academy of Sciences = Académie polonaise des sciences
- Proudman Oceanographic Laboratory
- Pôle Planétologie du LESIA