It took four satellites 16 years to collect more data than you can possibly hope to fit on a USB stick, but the US Geological Survey has finally completed the most detailed geological survey of the surface of Mars the human race has ever seen. Well done them.
Over a series of highly complex, frighteningly expensive missions, the Mars Global Surveyor, Mars Odyssey, Mars Express and Mars Reconnaissance Orbiter have peered and peeked into every ancient nook and dust-strewn cranny on the surface of our nearest planetary neighbour in the hope of learning something of its past.
As seen in the images above, this isn't your standard OS map. Details on the ages of the planet's surface and factors of erosion are indicated in a swirl of lines and colours. The most significant discoveries included a drastic re-evaluation of the age of the planet's surface - a vast portion of the wind-swept landscape is over 4 billion years old. The survey also lent further evidence to the belief that water was an active agent on the surface of Mars until recently (which, in space terms, was still ages ago).
Click here to see the map in one terrifyingly-big PDF file.