Explained: What is a ‘marsquake’, and what causes it?

How a marsquake takes place. (Source: NASA/JPL-Caltech/ETH Zurich/ Van Driel)

What are marsquakes, and why do they happen?

On Earth, quakes are caused by shifts in tectonic plates. Mars, however, does not have tectonic plates, and its crust is a giant plate. Therefore, NASA notes, ‘marsquakes’ are caused due to stresses that cause rock fractures or faults in its crust.

“Since we set our seismometer down in December 2018, we’ve been waiting for ‘the big one,’” Bruce Banerdt, InSight’s principal investigator at NASA’s Jet Propulsion Laboratory, said in a statement. “This quake is sure to provide a view into the planet like no other. Scientists will be analysing this data to learn new things about Mars for years to come.”

What is InSight doing on Mars?

InSight is not looking for life on Mars, but is studying what Mars is made of, how its material is layered, and how much heat seeps out of it.

This is important because Earth and Mars used to be similar — warm, wet and shrouded in thick atmospheres — before they took different paths 3-4 billion years ago. Mars stopped changing, while Earth continued to evolve.

With InSight, scientists hope to compare Earth and Mars, and better understand how a planet’s starting materials make it more or less likely to support life.

There are other missions to Mars that are looking for life on the planet, which makes Insight’s mandate unique. It mostly boils down to the possibility that the atmosphere of Mars was once warm enough to allow water to flow through its surface, which could mean life existed there too.

In fact, what makes scientists curious about Mars is the “defining question” of the existence of life on the planet, because of the possible presence of liquid water on it, either in the past or preserved in its subsurface. This question makes the planet more intriguing for scientists since “almost everywhere we find water on Earth, we find life,” as NASA puts it.

Further, if Mars harboured a warmer atmosphere enabling water to flow in its ancient past (3.5-3.8 billion years ago), and if microbial life existed on it, it is possible that it exists in “special regions” even today. But regardless of life having existed on Mars or not, there is the idea that humans themselves might be able to inhabit the planet one day.

Some missions studying the possibility of life on Mars include UAE’s Hope, China’s Tianwen-1, and NASA’s Perseverance.

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