Nasa’s Mars probe hears unusual noises and detects ‘Marsquakes’
Image credit: nasa
Nasa’s InSight lander has detected over 100 seismic signals since it landed in November 2018, with many of them thought to be 'Marsquakes' while the origin of others is still being debated by scientists.
The spacecraft is equipped with an extremely sensitive seismometer, called the Seismic Experiment for Interior Structure (SEIS), that can pick up vibrations as subtle as a breeze.
From the events it has detected, 21 are strongly considered to be quakes while the source of some of the other detected noises is less clear.
The quakes suggest that the Martian crust is like a mix of the Earth’s crust and that of the Moon. Cracks in the Earth’s crust seal over time as water fills them with new minerals. This enables sound waves to continue uninterrupted as they pass through old fractures.
Drier crusts like the Moon’s remain fractured after impacts, scattering sound waves for tens of minutes rather than allowing them to travel in a straight line. Mars, with its cratered surface, is slightly more Moon-like, with seismic waves ringing for a minute or so, whereas quakes on Earth can come and go in seconds.
Some of the other more unusual noises may emanate from gusts of wind or the creaking of the probe itself as its metal casing expands and contracts due to the changing temperatures.
“It’s been exciting, especially in the beginning, hearing the first vibrations from the lander,” said Constantinos Charalambous, an InSight science team member at Imperial College London. “You’re imagining what’s really happening on Mars as InSight sits on the open landscape.”
The craft also includes a German drilling instrument, although it has been inactive for months. Scientists are trying to salvage the experiment to measure the planet’s internal temperature.
The so-called mole is meant to penetrate 16ft beneath the Martian surface, but so far has managed barely 1ft.
Researchers suspect the Martian sand is not providing the necessary friction for digging, causing the mole to helplessly bounce around rather than burrow deeper, and to form a wide pit around itself.
Sign up to the E&T News e-mail to get great stories like this delivered to your inbox every day.