EnvironmentArt: Why Tomás Saraceno is floating on air Forget doomy "Anthropocene" ideas, if we're serious about saving Earth we need hope, says Tomás Saraceno, the artist whose tetrahedral balloons inspire researchers Culture
SpaceThe Martians have landed in London, and they're hogging the camera Artist Jenna Sutela has used Mars-friendly bacteria to grow an alien culture, rich in music and poetry – but is it any good? Culture