LOS ANGELES - No one knows if there are spiders on Mars, but now we know that there might be "marsquakes."
For the first time, NASA's Mars InSight lander has successfully measured and recorded what seems to be a temblor on the red planet.
The seismic signal was detected and recorded on April 6 by the lander's Seismic Experiment for Interior Structure, otherwise known as SEIS instrument, according to NASA.
NASA says that this is the first recorded seismic activity that appears to definitely have come from inside the planet rather than being caused by outside forces such as wind.
The Paris Institute of Earth Physics' Philippe Lognonne, who is in charge of the experiment, said it's exciting to finally have proof that Mars is still seismically active.
Mars is not nearly as geologically active as Earth and, like our moon, lacks tectonic plates.
Quakes occur on Earth on faults due to the motion of those tectonic plates. Because Mars doesn't have any, a continual process of cooling and contraction creates stress that builds over time, eventually leading to a break in the crust which can lead to a "marsquake," according to NASA.
Several other seismic events have been recorded on Mars but are much more ambiguous.
"You can hear sounds from the Very Broad Band sensors from your left speakers and sounds from the Short Period sensors from your right speakers," NASA says on its website.
InSight's lead scientist, Bruce Banerdt of NASA's Jet Propulsion Laboratory in Pasadena, California, said this carries out the scientific work begun by the Apollo moon-walkers nearly a half-century ago.
Researchers are still analyzing the data, as well as three other even fainter seismic signals detected since mid-March. By analyzing "marsquakes," scientists hope to learn more about how rocky planets formed.
The Associated Press contributed to this story