september: galileo's lunar legacy

This month, NASA's Galileo probe ends its highly successful mission to Jupiter in a blaze of glory. Its flight controllers, worried about the remote possibility of it contaminating Jupiter's moon Europa should they lose control as it's power fails, will deliberately burn it up in Jupiter's atmosphere.

During its mission, Galileo was used to study the jovian moons Ganymede, Callisto, Io, and Europa, first discovered by the probe's namesake Galileo Galilei.

But back in 1992, long before reaching these remote moons, it flew past Earth's own Moon. This false-colour image is a composite of four taken during that brief encounter. The colours are intended to highlight the mineralogy of the lunar soils, ranging from the red uplands (indicating low titanium and iron content) through orange (higher iron, as in the Mare Serenitatis, lower right) to blue (titanium-rich, such as the Mare Tranquillitatis, upper left).

Image: NASA.