First contact in space: Mir takes on supplies while Sojourner gets in touch with Martian geology

Nuzzling was the order of the day in space yesterday. On Mars, the tiny rover vehicle sidled up to a 3.5 billion-year-old rock - and began to examine it by bombarding the stone with radiation.

Meanwhile, 250 miles above the Earth, the three astronauts on board the damaged Mir space station docked, as delicately as possible, with a cargo ship carrying two tonnes of much-needed supplies - including tools and toothpaste. The tools are needed to help restore some of the power lost last month when a similar docking procedure went wrong and punched a hole in one of Mir's six modules.

Sojourner, the Mars rover, began the day by using its X-ray spectrometer to examine the powdery red soil at the base of the Pathfinder lander's ramp early yesterday morning. It was then taken 30 centimetres by its controllers back on Earth to a pockmarked rock, dubbed "Barnacle Bill". There, the chemical examination of the rocks around the lander, and of the soil, began in earnest.

The short journey, controlled by a team 119 million miles away, demonstrated that the rover was working perfectly after its parent spacecraft's 600mph landing on Friday, and the resetting of its computers when at first it failed to function, at the weekend.

The Sojourner sent back a signal confirming it had made contact with the rock, which it then examined for 10 hours.

The rover's spectrometer generates alpha-particle radiation with which it bombards small areas of rock or soil. It then looks for the patterns and types of particles that are bounced back. Each element generates a unique pattern of "bounced" particles, letting scientists build up a picture of the mineral constituents of any object.

Colin Pillinger, head of the Open University's Planetary Sciences Research Institute, said: "The scientists were aiming for this valley because they believe there was once water there. Barnacle Bill was probably deposited three-and-a-half billion years ago when they think there was a great flood there."

Scientists confirmed that the area around the Pathfinder landing site was hit by devastating floods billions of years ago. Michael Malin, one of the scientists, speculated the flooding was hundreds of miles wide and sent water surging at a rate of about 35 million cubic feet per second.

Yesterday's rendezvous at the Mir space stationattracted a large media contingent, and several ranking government officials to Mission Control, just outside Moscow, who watched on a giant screen as the two spacecraft approached each other above Siberia.

Today the astronauts will start unloading the supplies, including oxygen, water, food and toothpaste - items requested by the British-born Michael Foale, who was in the Spektr module on 25 June when a manual docking practice went wrong. All his personal items and science experiments are locked inside the depressurised module.