SEEING IS BELIEVING by Klaus Brasch BACKG RO U N D : ESA / D LR / FU B E R LIN , CC BY- SA 3 .0 IGO; S K E TC HES: PE R C I VA L LOW E LL / W I K I M E D I A C O M M O N S / PU B LI C D O M A I N Canal Earthly events influenced how astronomers perceived the Martian landscape a century ago. 28 J U LY 2 0 1 8 * S K Y & T E L E S C O P E