Goodbye home: Venus Express looks back on Earth

Images taken by one of the instruments onboard Venus Express show the Earth illuminated by the Sun, and the Moon.

Ground controllers are checking out the spacecraft's payload ahead of its arrival at Venus next year.

The spacecraft will study the planet's hostile atmosphere, which has experienced runaway greenhouse warming.

The images were taken by the VIRTIS Ultraviolet/Visible/Near-Infrared mapping spectrometer on 23 November, when the space craft was 3.5 million km (2.2 million miles) away from the Earth.

They will be used as test pictures to compare with those of Venus itself, once the probe gets closer to its target planet.

"A comparison of Venus spectra with Earth spectra with the same instrument will also be of interest for textbook illustration of the comparison between the two planets," said Pierre Drossart, one of the two principal investigators on the instrument.

Mission guide: Venus Express

Scientists hope the two-year mission will shed further light on the mechanisms of climate change on our own world.

Venus is almost identical in size to the Earth, and is thought to have a similar composition. But there the resemblance ends.

A dense, largely carbon dioxide, atmosphere acts as a blanket, trapping incoming solar radiation to heat the planet's surface to an average temperature of 467C (872F).

Surface pressure is about 90 times that on Earth. By studying this hostile world, scientists hope to understand better how a warming future on our own planet might evolve.