NASA's robotic probe InSight has detected and measured what scientists believe to be a "marsquake" marking the first time a likely seismological tremor has been recorded on another planet, the Jet Propulsion Laboratory (JPL) in California reported.
The breakthrough came on Tuesday nearly five months after InSight, the first spacecraft designed specifically to study the deep interior of a distant world, touched down on the surface of Mars to begin its two-year seismological mission on the Red Planet.
The faint rumble characterised by JPL scientists as a likely marsquake, roughly equal to a 2.5 magnitude earthquake, was recorded on April 6, the lander's 128th Martian day.
It was detected by InSight's French-built seismometer, an instrument sensitive enough to measure a seismic wave just one-half the radius of a hydrogen atom.
"We've been collecting background noise up until now, but this first event officially kicks off a new field: Martian seismology," InSight principal investigator Bruce Banerdt said in a news release.
Scientists are still examining the data to conclusively determine the precise cause of the signal, but the trembling appeared to have originated from inside the planet, as opposed to being caused by forces above the surface, such as wind.
NASA's InSight probe landed on the Red Planet in November last year.
InSight's mission is to identify the quakes that take place on the planet, with the aim to build a clearer picture of Mars's interior structure.
By studying Mars at its core, InSight aims to go back in time and shed light on what factors resulted in producing an Earth full of life and a desolate Mars.
"The information collected will help us to understand the evolution of rocky planets inside and outside our solar system," Rafael Navarro-Gonzalez, a member of the Curiosity mission and a researcher at the Institute of Nuclear Sciences in the National Autonomous University of Mexico (UNAM), told Al Jazeera, adding that the gathered date will help open a window into understanding life.
"Rocky planets like ours are essential for the emergence and evolution of life as we know it.
"Our goal is to find a second genesis of life, and we believe that Mars is the [place] where we can find it. In this way, we could revolutionise the biology from terrestrial to universal," Navarro-Gonzalez added.
No tectonic plates
The size and duration of the marsquake also fit the profile of some of the thousands of moonquakes detected on the lunar surface between 1969 and 1977 by seismometers installed there by NASA's Apollo missions, said Lori Glaze, planetary science division director at NASA headquarters in Washington.
The lunar and Martian surfaces are extremely quiet compared with Earth, which experiences constant low-level seismic noise from oceans and weather as well as quakes that occur along subterranean fault lines created by shifting tectonic plates in the planet's crust.
Mars and the moon lack tectonic plates. Their seismic activity is instead driven by a cooling and contracting process that causes stress to build up and become strong enough to rupture the crust.
Three other apparent seismic signals were picked up by InSight on March 14, April 10 and April 11 but were even smaller and more ambiguous in origin, leaving scientists less certain they were actual marsquakes.
