What Would Happen If the Moon Disappeared?

Tonight, the Moon is gone. The sky looks almost the same, so why do scientists say the real damage would take millions of years? This thought experiment sorts every effect by when it arrives: darker nights and corals losing their spawning cue on the first night; gentler, Sun-only tides and a day that lengthens more slowly over the first years; and, over millions of years, an axial tilt free to wander. We follow the 1993 Nature study that called the Moon a potential climate regulator, and the 2012 simulations that found moonless Earths far steadier than feared. No known process could make the Moon vanish; this is a way to ask what it actually does for us. Sources: Kyba et al. (2017), Kaniewska et al. (2015), NASA planetary fact sheets, NOAA, NASA lunar laser ranging, Stephenson et al. (2016), NASA Science (Milankovitch cycles), Laskar, Joutel & Robutel (Nature, 1993), Lissauer, Barnes & Chambers (Icarus, 2012). 0:00 Tonight the Moon is gone 0:37 What changes on the first night? 2:11 What happens to the tides? 3:33 Why is our day getting longer? 4:51 What keeps Earth from tipping over? 6:17 So do we really need the Moon?