No doubt most you are ready to stop thinking about Earth, this globally warming vale of tears, this stage mobbed with grunting masses and their incessant talk of fears and threats, this scene of fracking frissons and landslide wreckage and internecine warfare. Cast your minds skyward, then, and contemplate the clean, cold heights of outer space. Consider your knowledge of Earth above the ground and Earth's planetary siblings. Now pit your knowledge against this Geo-Whiz Quiz about space geology. If you feel a bit breathless, take your time.