Scientists marvel at crisp Mars photographs

Scientists marvelled at crisp photographs of the surface of Mars while the NASA rover that took them switched from black-and-white to colour as it continued to send back images of the pancake-flat plain where it landed.

NASA said it hoped to release the initial batch of colour photos – the first from the surface of Mars in seven years – later today.

The new images from the Spirit rover showed further details of what scientists believe is the rocky bed of an ancient lake that may have once harboured life.

The golf cart-sized Spirit landed on Mars late on Saturday, safely returning the National Aeronautics and Space Administration to the planet’s surface for the first time since the 1997 Pathfinder mission.

Just three hours after the unmanned robot landed, it began zipping 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 Julie Townsend, a mission avionics engineer.

The first images from Spirit show a flat, wind-scoured plain peppered with small rocks, none more than a foot high. The scene enthused scientists, 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 Wendy Calvin, of the University of Nevada, a scientist on the mission.

Calvin said the terrain appeared flatter and featured fewer and smaller rocks than the sites that Pathfinder and, in 1976, the twin Viking landers visited.

Late last night, NASA successfully established a link from Earth with Spirit’s high-gain antenna.

The link allows NASA to shuttle data directly between Spirit and Earth at transmission rates greater than 11,000 bits per second – about one-fifth the rate of a 56K dial-up connection to the internet on Earth.

Spirit’s fastest connection, at 128K, is expected to be through its UHF antenna. The antenna transmits data to the Mars Global Surveyor and 2001 Mars Odyssey spacecraft for later relay to Earth. The two satellites are in orbit around Mars.

The €710m NASA Mars Exploration Rover project also includes a twin golf cart-sized rover, Opportunity.

Spirit made an apparently flawless landing in Gusev Crater, an Israel-sized basin scientists believe once contained a brimming lake.

There were a few minor concerns about the mission. Scientists were trying to determine whether a dark object lodged against one corner of the lander was a rock that might block the rover once it is ready to move.

Over the next three months, the robot geologist should look for geological evidence of past water activity in the rocks and soil it was designed to analyse with its suite of instruments. If water once filled Gusev Crater, it may have been a place suitable for life.

As early as today, Spirit could be told to raise itself up – a two-day process - and extend its front legs. It will take nine to 10 days before the six-wheeled robot is ready to roll off its lander and begin roaming Mars.

Spirit’s successful landing bucked a trend of failed missions to Mars. 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.