Barometer | 1 October 2015
From our UK edition
Water worlds Nasa announced it had found evidence of running water on Mars in the form of dark streaks on mountains and cliff edges. On which other planets and celestial bodies can you slake your thirst? — Ganymede, a moon of Jupiter, is believed to have an ocean of liquid water 60 miles deep, beneath 90 miles of ice. — Two other moons of Jupiter, Europa and Callisto, are also believed to have liquid oceans beneath ice crusts, the former having more water than Earth. No other planets in our solar system, however, are believed to have liquid surface water. Card check How many members does Labour have?