NASA says goodbye to 'Oppy', lost in a Martian dust storm after 14 years on the job

NASA has finally said goodbye to its Opportunity Rover, which stopped responding eight months ago after a severe dust storm on Mars.

"Oppy", as the rover was affectionately known by those who were involved in the programme, was in operation for about 14 years after reaching the red planet, and roamed further than the distance of a marathon - 42km - during its lifetime.

Contact was lost with Oppy eight months ago, and NASA yesterday NZT formally ended the programme.

"We have made every reasonable engineering effort to try to recover Opportunity and have determined that the likelihood of receiving a signal is far too low to continue recovery efforts," NASA's Manager of the Mars Exploration Rover project John Callas said.

The rover was enveloped in a huge dust storm, which likely blocked out its solar panels, leaving a thick layer on top that couldn't be removed - or the dust may have affected the internal clock inside the rover.

Oppy was only designed with a 90-day mission in mind, so the 14 years it spent exploring far exceeded expectations.

It had a twin - Spirit - which also landed in 2004, but Spirit stopped working in 2010.

The two rovers made numerous discoveries on Mars, including the presence of gypsum - a compound formed from mineral-rich water - as well as spherical rock formations which strongly suggested that liquid water once flowed there.