The first pictures from the surface began to be fed back immediately 
BBC News - Nasa's Curiosity rover successfully lands on Mars
The US space agency has just landed a huge new robot rover on Mars.
The one-tonne vehicle, known as Curiosity, touched down at 0614 BST (0514 GMT) in a deep crater near the planet's equator after a plunging through the atmosphere.It is going to look for evidence that Mars could once have supported life.
A signal confirming the rover was on the ground safely was relayed to Earth via Nasa's Odyssey satellite, which is in orbit around the Red Planet.
The success was greeted with a roar of approval here at mission control at the Jet Propulsion Laboratory in Pasadena, California.
The mission has even already sent its first low-resolution images - showing the rover's wheel and its shadow, through a dust-covered lens cap that has yet to be removed.
A first colour image of Curiosity's surroundings should be returned in the next couple of days.
Engineers and scientists who have worked on this project for the best part of 10 years punched the air and hugged each other.
The descent through the atmosphere after a 570-million-km journey from Earth had been billed as the "seven minutes of terror" - the time it would take to complete a series of high-risk manoeuvres that would slow the rover from an entry speed of 20,000km/h to allow its wheels to set down softly.
After the landing, the flight director reported that Curiosity had set down at a gentle 0.6 metres per second.
"We're on Mars again, and it's absolutely incredible," said Nasa director Charles Bolden. "It doesn't get any better than this."
The mission team will now spend the next few hours assessing the health of the vehicle (also referred to as the Mars Science Laboratory, MSL).
Curiosity - Mars Science Laboratory
- Mission goal is to determine whether Mars has ever had the conditions to support life
- Project costed at $2.5bn; will see initial surface operations lasting two Earth years
- Onboard plutonium generators will deliver heat and electricity for at least 14 years
- 75kg science payload more than 10 times as massive as those of earlier US Mars rovers
- Equipped with tools to brush and drill into rocks, to scoop up, sort and sieve samples
- Variety of analytical techniques to discern chemistry in rocks, soil and atmosphere
- Will try to make first definitive identification of organic (carbon rich) compounds
- Even carries a laser to zap rocks; beam will identify atomic elements in rocks
This is the fourth rover Nasa has put on Mars, but its scale and sophistication dwarf all previous projects.
Curiosity has been sent to investigate the central mountain inside Gale Crater that is more than 5km high.
It will climb the rise, and, as it does so, study rocks that were laid down billions of years ago in the presence of liquid water.
The vehicle will be looking for evidence that past environments could have favoured microbial life.
Scientists warn, however, that this will be a slow mission - Curiosity is in no hurry.
For one thing, the rover has a plutonium battery that should give it far greater longevity than the solar-panelled power systems fitted to previous vehicles.
"People have got to realise this mission will be different," commented Steve Squyres, the lead scientist of the Opportunity and Spirit rovers landed in 2004.
"When we landed we only thought we'd get 30 sols (Martian days) on the surface, so we had to hit the ground running. Curiosity has plenty of time," he told the BBC.
Initially, the rover is funded for two years of operations. But many expect this mission to roll and roll for perhaps a decade or more.
- (A) Curiosity will trundle around its landing site looking for interesting rock features to study. Its top speed is about 4cm/s
- (B) This mission has 17 cameras. They will identify particular targets, and a laser will zap those rocks to probe their chemistry
- (C) If the signal is significant, Curiosity will swing over instruments on its arm for close-up investigation. These include a microscope
- (D) Samples drilled from rock, or scooped from the soil, can be delivered to two hi-tech analysis labs inside the rover body
- (E) The results are sent to Earth through antennas on the rover deck. Return commands tell the rover where it should drive next
