Y
- YardangA yardang is a streamlined protuberance carved from bedrock or any consolidated or semicon
- Yarkovsky effectForce on a rotating celestial body due to asymmetric thermal radiation
- Yellow supergiantStar that has a supergiant luminosity class, with a spectral type of F or G
- Yinghuo-1Yinghuo-1 (simplified Chinese: 萤火一号; traditional Chinese: 螢火一號; pinyin: Yínghuǒ yī hào) wa
- YORP effectThe Yarkovsky–O'Keefe–Radzievskii–Paddack effect, or YORP effect for short, changes the ro
- Yoshisada ShimizuJapanese astronomer
- You-Hua ChuUS and Taiwanese astronomer
- Young stellar objectStar in its early stage of evolution
- Yusuke HagiharaJapanese celestial mechanician