NASA's InSight lander places first instrument on Mars

NASA's InSight lander has deployed its first instrument onto the surface of Mars, completing a major mission milestone that will allow scientists to peer into the Martian interior by studying ground motion -- also known as marsquakes, the U.S space agency said.

New images from the lander show the seismometer on the ground, its copper-coloured covering faintly illuminated in the Martian dusk, NASA said in a statement.

"InSight's timetable of activities on Mars has gone better than we hoped," said InSight Project Manager Tom Hoffman, who is based at NASA's Jet Propulsion Laboratory (JPL).

"Getting the seismometer safely on the ground is an awesome Christmas present," said Hoffman.

The InSight team has been working carefully towards deploying its two dedicated science instruments onto Martian soil since landing on Mars on November 26.

The Rotation and Interior Structure Experiment (RISE), which does not have its own separate instrument, has already begun using InSight's radio connection with Earth to collect preliminary data on the planet's core.

Not enough time has elapsed for scientists to deduce what they want to know -- scientists estimate they might have some results starting in about a year, according to NASA.