There may be, or may have been, water on Mars but a debate over apparent shorelines on the planet’s vast northern plains continues, with new research suggesting the features have nothing to do with what others have interpreted as a one-time enormous ocean. The author of the new analysis of gentle, parallel ridges in the blandest, flattest northern plains of enigmatic Mars argues instead that the features are large landscape bumps that resulted simply to relieve surface pressure from massive volcanoes, such as Tharsis, and other structures on the planet’s surface.