Nasa’s new Mars lander has placed a quake monitor on the planet’s dusty red surface.
The milestone occurred less than a month after Mars InSight’s touchdown.
InSight’s robotic arm removed the seismometer from the spacecraft deck and set it on the ground on Wednesday to monitor Mars quakes.
Project manager Tom Hoffman called it “an awesome Christmas present”.
It is the first time a robotic arm has lowered an experiment on to the Martian surface.
The ground is slightly tilted so flight controllers still need to make the seismometer level.
InSight’s arm will swing back into action next month to place a wind cover over the seismometer and to set down another experiment.
The heat probe, dubbed the mole, will burrow up to 16ft into Mars to measure internal temperatures.