Nasa scientists have unveiled unprecedented close-up images of a massive crater on Mars they said could open the book on the Red Planet, from its formation to its history with water, the basis of life on Earth. The images, released on Friday, were taken three days ago by the Mars Reconnaissance Orbiter, which arrived in its permanent Martian orbit this week after an August 2005 launch and just turned its cameras on, and by a robotic rover on the planet's surface. The Victoria crater is the biggest crater the Nasa will probably get to with its two rovers on the Martian surface.