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| Phoenix Mars probe touches down | Phoenix Mars probe touches down |
| (10 minutes later) | |
| The US space agency Nasa has landed a spacecraft on the surface of Mars. | The US space agency Nasa has landed a spacecraft on the surface of Mars. |
| The Mars Phoenix lander touched down late on Sunday GMT in the far north of the Red Planet, after a 680-million-km (423-million-mile) journey from Earth. | The Mars Phoenix lander touched down late on Sunday GMT in the far north of the Red Planet, after a 680-million-km (423-million-mile) journey from Earth. |
| The probe is equipped with a robotic arm to dig for water-ice thought to be buried beneath the surface. | The probe is equipped with a robotic arm to dig for water-ice thought to be buried beneath the surface. |
| Scientists say the mission should give the clearest indication yet of whether the planet could once have harboured primitive life. | Scientists say the mission should give the clearest indication yet of whether the planet could once have harboured primitive life. |
| A signal confirming the Phoenix lander had reached the surface of Mars was received at 2353 GMT on 25 May (1953 EDT; 0053 BST on 26 May). | A signal confirming the Phoenix lander had reached the surface of Mars was received at 2353 GMT on 25 May (1953 EDT; 0053 BST on 26 May). |
| In my dreams it couldn't have gone as perfectly as it did tonight Barry Goldstein, Phoenix project manager at JPL | In my dreams it couldn't have gone as perfectly as it did tonight Barry Goldstein, Phoenix project manager at JPL |
| Engineers and scientists at Nasa's Jet Propulsion Laboratory in California clapped and cheered when the landing signal came through. | Engineers and scientists at Nasa's Jet Propulsion Laboratory in California clapped and cheered when the landing signal came through. |
| "Phoenix has landed - welcome to the northern plain of Mars," a flight controller announced. | "Phoenix has landed - welcome to the northern plain of Mars," a flight controller announced. |
| Fiery plunge | Fiery plunge |
| The final seven minutes of the probe's 10-month journey to Mars were regarded as the hardest part of the mission. | The final seven minutes of the probe's 10-month journey to Mars were regarded as the hardest part of the mission. |
| The probe had to survive a fiery plunge through the planet's thin atmosphere, slowing from a speed of nearly 21,000km/h (13,000 mph). | The probe had to survive a fiery plunge through the planet's thin atmosphere, slowing from a speed of nearly 21,000km/h (13,000 mph). |
| It released a parachute, used pulsed thrusters to slow to a fast walking speed, then descended the last few metres to the Martian soil to land on three legs. | It released a parachute, used pulsed thrusters to slow to a fast walking speed, then descended the last few metres to the Martian soil to land on three legs. |
| Phoenix landed further north than previous missions | Phoenix landed further north than previous missions |
| The Nasa team monitored each stage of the descent and landing process through radio messages relayed to Earth via the Odyssey satellite in orbit around Mars. | The Nasa team monitored each stage of the descent and landing process through radio messages relayed to Earth via the Odyssey satellite in orbit around Mars. |
| "In my dreams it couldn't have gone as perfectly as it did tonight," said Barry Goldstein, Phoenix project manager at JPL. | "In my dreams it couldn't have gone as perfectly as it did tonight," said Barry Goldstein, Phoenix project manager at JPL. |
| Nasa will find out more about the details of the landing in the next few hours, when pictures from the probe reach the Earth. | Nasa will find out more about the details of the landing in the next few hours, when pictures from the probe reach the Earth. |
| The first images will be of the craft itself, to show Nasa if all the equipment is in working order, and then, possibly, the first shots of the arctic plain where Phoenix came to rest. | The first images will be of the craft itself, to show Nasa if all the equipment is in working order, and then, possibly, the first shots of the arctic plain where Phoenix came to rest. |
| Water search | Water search |
| If all goes to plan, the spacecraft will open its solar arrays and begin powering the battery for the three-month science mission. | If all goes to plan, the spacecraft will open its solar arrays and begin powering the battery for the three-month science mission. |
| Phoenix carries seven science instruments | Phoenix carries seven science instruments |
| It will use a robotic arm to dig through the protective Martian topsoil and lift samples of both soil and ice to its deck for scientific analysis. | It will use a robotic arm to dig through the protective Martian topsoil and lift samples of both soil and ice to its deck for scientific analysis. |
| Dr Tom Pike of Imperial College, London, is part of the British team involved in the project. | Dr Tom Pike of Imperial College, London, is part of the British team involved in the project. |
| "The main goal of the mission is to get below the surface of Mars to where we are almost certain there is water," he told BBC News. | "The main goal of the mission is to get below the surface of Mars to where we are almost certain there is water," he told BBC News. |
| He said orbiters flying around Mars had surveyed the landing site in great detail and found signs that water ice is buried 10cm or less below the surface. | He said orbiters flying around Mars had surveyed the landing site in great detail and found signs that water ice is buried 10cm or less below the surface. |
| "Water, of course, is of critical importance because it is one of the building blocks - one of the essential habitats we need - for life," he said. | "Water, of course, is of critical importance because it is one of the building blocks - one of the essential habitats we need - for life," he said. |
| High failure rate | High failure rate |
| Landing on Mars is a notoriously tricky business. There has been about a 50% failure rate on all Mars missions since Russia launched the first one in 1960. | Landing on Mars is a notoriously tricky business. There has been about a 50% failure rate on all Mars missions since Russia launched the first one in 1960. |
| Phoenix is an apt name for the current mission, as it rose from the ashes of two previous failures. | Phoenix is an apt name for the current mission, as it rose from the ashes of two previous failures. |
| In September 1999, the Mars Climate Orbiter spacecraft crashed into the Red Planet following a navigation error caused when technicians mixed up "English" (imperial) and metric units. | In September 1999, the Mars Climate Orbiter spacecraft crashed into the Red Planet following a navigation error caused when technicians mixed up "English" (imperial) and metric units. |
| A few months later, another Nasa spacecraft, the Mars Polar Lander (MPL), was lost near the planet's South Pole. | A few months later, another Nasa spacecraft, the Mars Polar Lander (MPL), was lost near the planet's South Pole. |
| Phoenix uses hardware from an identical twin of MPL, the Mars Surveyor 2001 Lander, which was cancelled following the two consecutive failures. | Phoenix uses hardware from an identical twin of MPL, the Mars Surveyor 2001 Lander, which was cancelled following the two consecutive failures. |
| The probe was launched on 4 August 2007 on a Delta II rocket from Cape Canaveral Air Force Station in Florida. | The probe was launched on 4 August 2007 on a Delta II rocket from Cape Canaveral Air Force Station in Florida. |