Using a highly sensitive seismometer, NASA's InSight has detected for the first time minute tremors that rock the surface of Mars.
The lander, which arrived on the Red Planet in November, discovered the microseisms in February. Scientists believe that the continuous rumbling is caused by low-frequency pressure waves from atmospheric winds that blow on the surface.
The findings were presented at the annual Lunar and Planetary Science Conference.
Microseisms Detected In Mars
Earth has similar microseisms, faint seismic signals that are ubiquitous and continuous, caused by wind-driven surface waves. While Mars has neither seas nor oceans, a similar "humming" was heard from the Red Planet.
InSight, which is short for Seismic Investigations, Geodesy, and Heat Transport, discovered the microseisms of Mars while trying to detect "marsquakes," the vibrations that occur underground. According to scientists, the quakes that occur in Mars are fundamentally different from the ones experienced on Earth.
On Earth, quakes happen because of plate tectonics or when the plates that make up the surface of the planet move over the mantle. However, Mars does not have the same broken outer shell. Instead, scientists believe that marsquakes happen because of different phenomena, such as the pressure of magma pushing upward to the surface or meteorite impacts.
NASA is hoping that marsquakes would help paint a picture of what Earth looked like during its early years.
InSight so far has not detected any marsquakes, but Philippe Lognnonné, the planetary seismologist behind the effort, said that finding the microseism is a major discovery. On Earth, scientists have started to see microseisms as more than just a nuisance, but something from which they can learn about features of the subsurface. Lognnonné explained that the microseisms can be as valuable to scientists studying Mars.
Scientists Waiting For The First Marsquake
Scientists are gearing for their first marsquake. The hypersensitive seismometer has been placed on the surface of Mars and the detection of microseisms in the Red Planet is proof that it is working. The team is expecting to detect about one marsquake a month.
NASA's InSight is the first Martian lander to conduct a thorough checkup of the insides of the Red Planet. It is equipped to study the vital signs of Earth's neighbor, including the pulse (seismology), temperature (heat flow), and reflexes (precision tracking).