Nasa has officially called an end to the Phoenix Mars mission after admitting that it has not heard from the probe in over a week.

The probe established that water exists on Mars and that a landing on the planet is possible under rocket power alone, something that could be crucial for planned human exploration.

"Phoenix not only met the tremendous challenge of landing safely, it accomplished scientific investigations on 149 of its 152 Martian days as a result of dedicated work by a talented team," said Phoenix project manager Barry Goldstein of Nasa's Jet Propulsion Laboratory in Pasadena.

The probe's current location means that its batteries are no longer receiving enough power to maintain a charge, and it is unlikely that it will revive in the spring because of the amount of dust that will contaminate the solar panels.

"Phoenix provided an important step to spur the hope that we can show that Mars was once habitable and possibly supported life," said Doug McCuistion, director of the Mars Exploration Programme at Nasa headquarters in Washington.

"Phoenix was supported by orbiting Nasa spacecraft providing a communications relay while producing their own fascinating science. With the upcoming launch of the Mars Science Laboratory, the Mars programme never sleeps."