‘New frontiers’ considers where the future lies for tidal studies. On our own planet there are discoveries to be made in difficult-to-reach places such as deep-sea ecosystems. The interaction between tides and sunlight in shallow water has been barely explored. Innovative computer models allow us to reproduce the tide in the early ocean. Tidal forces are not confined to Earth. Tidal flexing of the icy moons of Jupiter appears to have created a liquid water ocean on Europa. It is possible that this ocean has the right conditions for life, and space probes planned for the next few years will be able to test this possibility.