This false-colour composite photograph of 15 images of the Moon was taken through three colour filters by the Galileo spacecraft Solid State Imaging system during its flyby through the Earth-Moon system on 7 December 1992. This view was obtained while the spacecraft was 425 000 km (262,000 miles) from the Moon and 69 000 km (43,000 miles) from the Earth.
The false colour processing of this image is useful for interpreting the surface soil composition. Areas in red generally correspond to the lunar highlands while blue to orange shades indicate volcanic lava (mare) flows. Bluer mare units contain more titanium than orange units. Mare Tranquillitatis, seen as a deep blue patch on the right, is more titanium-rich than Mare Serenitatis, a slightly smaller circular area immediately adjacent to the upper left of Mare Tranquillitatis. Blue and orange areas covering much of the left side of this view represent many separate lava flows in Oceanus Procellarum. The small purple units, found near the centre, are pyroclastic deposits formed by explosive volcanic eruptions. The fresh crater Tycho (diameter 85 km) is prominent at the bottom of this view. Photo: NASA