American scientists hope to release an initial batch of colour photos today taken on Mars to give the first colour images from the surface of the Red Planet in seven years.
The latest images from the Spiritrover show further details of what scientists believe is the rocky bed of an ancient lake that may have once harboured life.
The golf cart-sized Spiritlanded on Mars late on Saturday, safely returning NASA to the planet's surface for the first time since the 1997 Pathfindermission.
Just three hours after the unmanned robot landed, it began sending the first black-and-white images of its surroundings to Earth, 106 million miles distant at the time.
"It was so gorgeous to see the horizon in the pictures. It's what we'd been imagining for so long," said Ms Julie Townsend, a mission avionics engineer.
This mosaic image taken by the navigation camera from Mars
The first images from Spiritshow a flat, wind-scoured plain peppered with small rocks, none more than a foot high. The scene enthused scientists, who are eager to send the rover prospecting among the rocks for evidence that the landing site was once awash in water.
"It's all stunning, it's all new and it's all different," said Ms Wendy Calvin, of the University of Nevada, a scientist on the mission.
Ms Calvin said the terrain appeared flatter and featured fewer and smaller rocks than the sites that Pathfinderand, in 1976, the twin Vikinglanders visited.
Late last night, NASA successfully established a link from Earth with Spirit's high-gain antenna.
Just one in three past attempts to land on the planet has succeeded. British scientists said they would keep trying to contact their probe, the Beagle 2, which was supposed to land on Mars on Christmas Day but has not been heard of since.
AP