As is often said by those with a flair for the dramatic: it begins.
NASA’s InSight robot, just a handful of months into its exciting geological exploratory mission on Mars, has made a literally groundbreaking discovery. As announced by NASA earlier today, it has likely heard a genuine quake on Mars for the first time. Much like scientists on terra firma, such quakes will let InSight peer through the planet’s subterranean realm, allowing them to visualise its somewhat enigmatic internal structure.
The signal, picked up by the lander’s incredibly sensitive and precise Seismic Experiment for Interior Structure (SEIS) instrument, was recorded on the lander’s 128th Martian day, on April 6 of this year. Plenty of rumblings had already been detected by the lander, but these were being generated by the wind as it lightly shook the rust-hued surface.
This time, however, it’s almost certainly the real deal, as its waveform – the shape of the signal – much more closely resembles a genuine quake, based on terrestrial and lunar data. This makes it the first time a quake has been detected on another planet other than our own.
“It will probably take a series of similar signals for us to be 100 percent certain that this is a quake,” Anna Horleston, a planetary seismologist and member of the InSight mission’s MarsQuakes Service Frontline Team, tells me. Saying that, the signal is “very different” from any others recorded on Mars, and it has plenty of features that make it a very likely candidate quake. At the same time, the lander was asleep at the time of the quake, and nothing local that scientists are aware of could create a tremor like this. “All of this strongly suggests it is a quake,” she adds.
It was a fairly weak signal, and right now there’s not enough information to say why this is; it’s perhaps because the signal came from far away, or that it was of a very low magnitude, or a bit of both.
Mark Panning, a planetary seismologist at NASA’s Jet Propulsion Laboratory, told me on Twitter that “it’s hard to know for sure” why the signal is so weak. They can’t yet properly identify individual components of the seismic signal, and researchers “don’t yet know Mars well enough to understand the characteristics of the waveforms.” It’s likely to be a result of multiple factors, though.
In any case, this monumental detection “means that we’ve now entered a new era of planetary geophysics,” says Paul Byrne, a planetary scientist at North Carolina State University not involved with the work. “With this finding by InSight, we have or are now listening to the interiors of three of the five major rocky bodies in the inner solar system” – meaning Earth, the Moon and now Mars.
This is just the start of a prolonged and no doubt revelatory mission. As time goes by, more marsquakes will be spied by InSight. “Hopefully, before very long, we’ll have a much better understanding not only of the interior of the Red Planet,” and of other rocky planets in general, says Byrne, within and outside of our cosmic backwater.
This article originally appeared on Forbes