Why haven't we found dozens of exomoons yet? With planets as small as the Moon having been detected by NASA's Kepler Mission, it's fair to wonder why we only know of a single exomoon candidate to date. Despite the lack of moon detections, there are actually hundreds of known planets that wobble around, a tell-tale sign that a moon could be present. Unfortunately, these wobbles can also be caused by other planets and so in a new research appear Prof Kipping and Alex Teachey have re-visited the theory behind exomoons and come up with a new trick to help us discern between the two - impossible moons. Presented & Written by Prof David Kipping. This video is based on research conducted at the Cool Worlds Lab at Columbia University, New York. You can now support our research program directly here: https://www.coolworldslab.com/support References: ► Kipping, D. & Teachey, A., 2020, "Impossible moons - Transit timing effects that cannot be due to an exomoon", MNRAS: https://arxiv.org/abs/2004.04230 ► Kipping, D., et al., 2015, "The Hunt for Exomoons with Kepler (HEK): V. A Survey of 41 Planetary Candidates for Exomoons", ApJ 813, 14 https://arxiv.org/abs/1503.05555 ► Kipping, D., et al. 2009, "On the detectability of habitable exomoons with Kepler-class photometry", MNRAS 400, 398: https://arxiv.org/abs/0907.3909 ► Kipping, D., 2009a, "Transit timing effects due to an exomoon", MNRAS 392, 181: https://arxiv.org/abs/0810.2243 ► Kipping, D., 2009b, "Transit timing effects due to an exomoon II", MNRAS 396, 1797: https://arxiv.org/abs/0904.2565 Video materials & graphics used: ► Exoplanet animation by ESO/L.Calçada/M.Kornmesser: https://www.eso.org/public/videos/eso1621a/ ► Exoplanet animation by ESO/P. Delorme/Nick Risinger/R. Saito/VVV Consortium: https://www.eso.org/public/videos/eso1245a/ ► Exoplanet animation by ESO/M. Kornmesser: https://www.eso.org/public/videos/eso1615b/ ► Perijove by NASA/Seán Doran: https://youtu.be/3kQbTBt418o ► Jupiter zoom ou